* src/twaalgos/safety.hh, src/twaalgos/safety.cc: Here.
* src/bin/ltlfilt.cc, src/tests/ikwiad.cc, src/twaalgos/minimize.cc,
wrap/python/ajax/spotcgi.in: Adjust.
* NEWS: Mention the change.

* doc/org/tut01.org, doc/tl/tl.tex, src/bin/common_r.hh,
src/bin/ltlfilt.cc, src/tests/equalsf.cc, src/tests/ikwiad.cc,
src/tests/randtgba.cc, src/tests/reduc.cc, src/tests/syntimpl.cc,
src/tl/nenoform.cc, src/tl/randomltl.cc, src/tl/randomltl.hh,
src/tl/simplify.cc, src/tl/simplify.hh, src/twaalgos/ltl2tgba_fm.cc,
src/twaalgos/ltl2tgba_fm.hh, src/twaalgos/stutter.cc,
src/twaalgos/translate.cc, src/twaalgos/translate.hh,
wrap/python/ajax/spotcgi.in, wrap/python/spot.py,
wrap/python/tests/interdep.py: Rename ltl_simplifier to tl_simplifier.
* NEWS: Mention it.

* NEWS: Mention it.
* bench/stutter/stutter_invariance_formulas.cc,
bench/stutter/stutter_invariance_randomgraph.cc, doc/mainpage.dox,
doc/org/tut01.org, doc/org/tut02.org, doc/org/tut10.org, doc/tl/tl.tex,
iface/ltsmin/ltsmin.cc, iface/ltsmin/ltsmin.hh,
iface/ltsmin/modelcheck.cc, src/bin/autfilt.cc,
src/bin/common_aoutput.cc, src/bin/common_aoutput.hh,
src/bin/common_finput.cc, src/bin/common_finput.hh,
src/bin/common_output.cc, src/bin/common_output.hh, src/bin/common_r.hh,
src/bin/common_trans.cc, src/bin/common_trans.hh, src/bin/dstar2tgba.cc,
src/bin/genltl.cc, src/bin/ltl2tgba.cc, src/bin/ltl2tgta.cc,
src/bin/ltlcross.cc, src/bin/ltldo.cc, src/bin/ltlfilt.cc,
src/bin/ltlgrind.cc, src/bin/randaut.cc, src/bin/randltl.cc,
src/kripke/kripkeexplicit.cc, src/kripke/kripkeexplicit.hh,
src/kripkeparse/kripkeparse.yy, src/kripkeparse/public.hh,
src/ltlparse/fmterror.cc, src/ltlparse/ltlparse.yy,
src/ltlparse/ltlscan.ll, src/ltlparse/parsedecl.hh,
src/ltlparse/public.hh, src/parseaut/parseaut.yy,
src/parseaut/public.hh, src/tests/checkpsl.cc, src/tests/checkta.cc,
src/tests/complementation.cc, src/tests/consterm.cc,
src/tests/emptchk.cc, src/tests/equalsf.cc, src/tests/ikwiad.cc,
src/tests/kind.cc, src/tests/length.cc, src/tests/ltlprod.cc,
src/tests/ltlrel.cc, src/tests/parse.test,
src/tests/parse_print_test.cc, src/tests/randtgba.cc,
src/tests/readltl.cc, src/tests/reduc.cc, src/tests/syntimpl.cc,
src/tests/taatgba.cc, src/tests/tostring.cc, src/tests/tostring.test,
src/tl/apcollect.cc, src/tl/apcollect.hh, src/tl/contain.cc,
src/tl/contain.hh, src/tl/declenv.cc, src/tl/declenv.hh,
src/tl/defaultenv.cc, src/tl/defaultenv.hh, src/tl/dot.cc,
src/tl/dot.hh, src/tl/environment.hh, src/tl/exclusive.cc,
src/tl/exclusive.hh, src/tl/formula.cc, src/tl/formula.hh,
src/tl/length.cc, src/tl/length.hh, src/tl/mark.cc, src/tl/mark.hh,
src/tl/mutation.cc, src/tl/mutation.hh, src/tl/nenoform.cc,
src/tl/nenoform.hh, src/tl/print.cc, src/tl/print.hh,
src/tl/randomltl.cc, src/tl/randomltl.hh, src/tl/relabel.cc,
src/tl/relabel.hh, src/tl/remove_x.cc, src/tl/remove_x.hh,
src/tl/simpfg.cc, src/tl/simpfg.hh, src/tl/simplify.cc,
src/tl/simplify.hh, src/tl/snf.cc, src/tl/snf.hh, src/tl/unabbrev.cc,
src/tl/unabbrev.hh, src/twa/bdddict.cc, src/twa/bdddict.hh,
src/twa/bddprint.cc, src/twa/formula2bdd.cc, src/twa/formula2bdd.hh,
src/twa/taatgba.cc, src/twa/taatgba.hh, src/twa/twa.hh,
src/twa/twagraph.cc, src/twa/twagraph.hh, src/twaalgos/compsusp.cc,
src/twaalgos/compsusp.hh, src/twaalgos/ltl2taa.cc,
src/twaalgos/ltl2taa.hh, src/twaalgos/ltl2tgba_fm.cc,
src/twaalgos/ltl2tgba_fm.hh, src/twaalgos/minimize.cc,
src/twaalgos/minimize.hh, src/twaalgos/neverclaim.cc,
src/twaalgos/postproc.cc, src/twaalgos/postproc.hh,
src/twaalgos/powerset.cc, src/twaalgos/powerset.hh,
src/twaalgos/randomgraph.cc, src/twaalgos/randomgraph.hh,
src/twaalgos/relabel.cc, src/twaalgos/relabel.hh,
src/twaalgos/remprop.cc, src/twaalgos/remprop.hh, src/twaalgos/stats.cc,
src/twaalgos/stats.hh, src/twaalgos/stutter.cc, src/twaalgos/stutter.hh,
src/twaalgos/translate.cc, src/twaalgos/translate.hh,
wrap/python/spot_impl.i: Remove the ltl namespace.

The ltl prefix does not make a lot of sens anymore (since we
support psl as well).  ltlast/ and ltlenv/ were almost empty.
And ltlvisit/ did not contain any visitor anymore.

* src/ltlvisit/, src/ltlast/, src/ltlenv/: Merge into...
* src/tl/: ...this.
* NEWS: Mention the change.
* README, bench/stutter/stutter_invariance_formulas.cc,
bench/stutter/stutter_invariance_randomgraph.cc, configure.ac,
doc/org/tut01.org, doc/org/tut02.org, doc/org/tut10.org, doc/tl/tl.tex,
iface/ltsmin/ltsmin.hh, iface/ltsmin/modelcheck.cc, src/Makefile.am,
src/bin/autfilt.cc, src/bin/common_output.cc, src/bin/common_output.hh,
src/bin/common_r.hh, src/bin/common_trans.cc, src/bin/genltl.cc,
src/bin/ltl2tgba.cc, src/bin/ltl2tgta.cc, src/bin/ltlcross.cc,
src/bin/ltldo.cc, src/bin/ltlfilt.cc, src/bin/ltlgrind.cc,
src/bin/randltl.cc, src/kripke/kripkeexplicit.hh,
src/kripkeparse/public.hh, src/parseaut/public.hh, src/priv/accmap.hh,
src/ta/taexplicit.hh, src/ta/tgtaexplicit.hh, src/tests/equalsf.cc,
src/tests/ikwiad.cc, src/tests/length.cc, src/tests/ltlrel.cc,
src/tests/randtgba.cc, src/tests/readltl.cc, src/tests/reduc.cc,
src/tests/syntimpl.cc, src/tests/taatgba.cc, src/tests/tostring.cc,
src/tests/twagraph.cc, src/twa/acc.hh, src/twa/bdddict.cc,
src/twa/bdddict.hh, src/twa/bddprint.cc, src/twa/taatgba.cc,
src/twa/taatgba.hh, src/twa/twa.hh, src/twa/twagraph.cc,
src/twa/twagraph.hh, src/twa/twasafracomplement.cc,
src/twaalgos/compsusp.cc, src/twaalgos/compsusp.hh,
src/twaalgos/dtgbasat.cc, src/twaalgos/hoa.cc,
src/twaalgos/isweakscc.cc, src/twaalgos/lbtt.cc,
src/twaalgos/ltl2taa.cc, src/twaalgos/ltl2taa.hh,
src/twaalgos/ltl2tgba_fm.cc, src/twaalgos/ltl2tgba_fm.hh,
src/twaalgos/minimize.hh, src/twaalgos/neverclaim.cc,
src/twaalgos/randomgraph.hh, src/twaalgos/relabel.hh,
src/twaalgos/remprop.hh, src/twaalgos/stats.cc, src/twaalgos/stutter.cc,
src/twaalgos/translate.hh, wrap/python/spot_impl.i,
src/ltlparse/ltlparse.yy, src/ltlparse/public.hh: Adjust.

Fixes #106.

* m4/gccwarn.m4: Use -Wzero-as-null-pointer-constant if supported.
* src/bin/autfilt.cc, src/bin/common_aoutput.cc,
src/bin/common_finput.cc, src/bin/common_finput.hh,
src/bin/common_output.cc, src/bin/common_output.hh,
src/bin/common_post.cc, src/bin/common_r.hh, src/bin/common_range.hh,
src/bin/common_setup.cc, src/bin/common_trans.cc, src/bin/dstar2tgba.cc,
src/bin/genltl.cc, src/bin/ltl2tgba.cc, src/bin/ltl2tgta.cc,
src/bin/ltlcross.cc, src/bin/ltldo.cc, src/bin/ltlfilt.cc,
src/bin/ltlgrind.cc, src/bin/randaut.cc, src/bin/randltl.cc,
src/bin/spot-x.cc, src/kripke/kripkeexplicit.cc, src/ltlast/formula.cc,
src/ltlvisit/randomltl.cc, src/ltlvisit/randomltl.hh,
src/ltlvisit/relabel.cc, src/ltlvisit/relabel.hh,
src/ltlvisit/simplify.cc, src/ltlvisit/snf.hh, src/misc/fixpool.hh,
src/misc/mspool.hh, src/misc/hash.hh, src/misc/optionmap.cc,
src/misc/satsolver.cc, src/misc/tmpfile.cc, src/misc/tmpfile.hh,
src/priv/bddalloc.cc, src/ta/ta.hh, src/ta/taexplicit.cc,
src/ta/taexplicit.hh, src/ta/taproduct.cc, src/ta/tgtaexplicit.hh,
src/ta/tgtaproduct.cc, src/taalgos/minimize.cc,
src/taalgos/reachiter.cc, src/taalgos/tgba2ta.cc,
src/tests/complementation.cc, src/tests/ikwiad.cc,
src/tests/randtgba.cc, src/tests/reduc.cc, src/twa/bdddict.cc,
src/twa/bddprint.cc, src/twa/taatgba.cc, src/twa/twa.cc,
src/twa/twagraph.hh, src/twa/twaproduct.cc,
src/twa/twasafracomplement.cc, src/twaalgos/bfssteps.cc,
src/twaalgos/compsusp.cc, src/twaalgos/dtgbasat.cc,
src/twaalgos/emptiness.cc, src/twaalgos/gtec/ce.cc,
src/twaalgos/gv04.cc, src/twaalgos/ltl2taa.cc,
src/twaalgos/ltl2tgba_fm.cc, src/twaalgos/ltl2tgba_fm.hh,
src/twaalgos/magic.cc, src/twaalgos/minimize.cc,
src/twaalgos/ndfs_result.hxx, src/twaalgos/postproc.cc,
src/twaalgos/postproc.hh, src/twaalgos/reachiter.cc,
src/twaalgos/reducerun.cc, src/twaalgos/safety.hh,
src/twaalgos/sccfilter.hh, src/twaalgos/se05.cc,
src/twaalgos/simulation.cc, src/twaalgos/tau03.cc,
src/twaalgos/tau03opt.cc, src/twaalgos/translate.cc,
src/twaalgos/translate.hh, utf8/utf8/core.h,
bench/stutter/stutter_invariance_formulas.cc, iface/ltsmin/ltsmin.cc,
iface/ltsmin/modelcheck.cc: Use nullptr to fix the warning.

Flatten the formula ltl::formula hiearchy into a single ltl::vnode that
has an enumerator to distinguish the types of node, and a common
interface to access children, update reference counts, etc.  The
ltl::formula class is now a thin wrapper around an ltl::vnode pointer to
keep track of reference counts automatically.  Visitor are not used
anymore; we now have map() and traversor() methods that are more
concise.

This basically fixes #43, but should be followed by some fine tuning
that should now be localized to the formula.hh and formula.cc files.

Some statistics about this patch.  I started working on it on Sep 9, had
a first compiling version two weeks later on Sep 22, and it then took 5
days to fixes the ~70 distincts bugs that were introduced during the
conversion.  About 13200 lines were modified, and one third of those
were removed.

* src/ltlast/formula.cc, src/ltlast/formula.hh: Complete rewrite,
including what was in separate nearby files.
* src/ltlast/allnodes.hh, src/ltlast/atomic_prop.cc,
src/ltlast/atomic_prop.hh, src/ltlast/binop.cc, src/ltlast/binop.hh,
src/ltlast/bunop.cc, src/ltlast/bunop.hh, src/ltlast/constant.cc,
src/ltlast/constant.hh, src/ltlast/multop.cc, src/ltlast/multop.hh,
src/ltlast/unop.cc, src/ltlast/unop.hh, src/ltlvisit/dump.cc,
src/ltlvisit/dump.hh, src/ltlast/predecl.hh: Delete these files.  Their
feature have been merged in formula.hh and formula.cc.
* src/ltlast/visitor.hh, src/ltlvisit/clone.cc, src/ltlvisit/clone.hh,
src/ltlvisit/dump.hh, src/ltlvisit/postfix.cc, src/ltlvisit/postfix.hh:
Delete these files, as we do not use visitors anymore.
* bench/stutter/stutter_invariance_formulas.cc,
bench/stutter/stutter_invariance_randomgraph.cc, doc/org/tut01.org,
doc/org/tut02.org, doc/org/tut10.org, doc/org/tut22.org,
iface/ltsmin/ltsmin.cc, iface/ltsmin/ltsmin.hh,
iface/ltsmin/modelcheck.cc, src/bin/autfilt.cc,
src/bin/common_aoutput.cc, src/bin/common_aoutput.hh,
src/bin/common_finput.cc, src/bin/common_finput.hh,
src/bin/common_output.cc, src/bin/common_output.hh,
src/bin/common_trans.cc, src/bin/common_trans.hh, src/bin/dstar2tgba.cc,
src/bin/genltl.cc, src/bin/ltl2tgba.cc, src/bin/ltl2tgta.cc,
src/bin/ltlcross.cc, src/bin/ltldo.cc, src/bin/ltlfilt.cc,
src/bin/ltlgrind.cc, src/bin/randaut.cc, src/bin/randltl.cc,
src/kripke/kripkeexplicit.cc, src/kripke/kripkeexplicit.hh,
src/kripkeparse/kripkeparse.yy, src/ltlast/Makefile.am,
src/ltlenv/declenv.cc, src/ltlenv/declenv.hh, src/ltlenv/defaultenv.cc,
src/ltlenv/defaultenv.hh, src/ltlenv/environment.hh,
src/ltlparse/ltlparse.yy, src/ltlparse/public.hh,
src/ltlvisit/Makefile.am, src/ltlvisit/apcollect.cc,
src/ltlvisit/apcollect.hh, src/ltlvisit/contain.cc,
src/ltlvisit/contain.hh, src/ltlvisit/dot.cc, src/ltlvisit/dot.hh,
src/ltlvisit/exclusive.cc, src/ltlvisit/exclusive.hh,
src/ltlvisit/length.cc, src/ltlvisit/length.hh, src/ltlvisit/mark.cc,
src/ltlvisit/mark.hh, src/ltlvisit/mutation.cc,
src/ltlvisit/mutation.hh, src/ltlvisit/nenoform.cc,
src/ltlvisit/nenoform.hh, src/ltlvisit/print.cc, src/ltlvisit/print.hh,
src/ltlvisit/randomltl.cc, src/ltlvisit/randomltl.hh,
src/ltlvisit/relabel.cc, src/ltlvisit/relabel.hh,
src/ltlvisit/remove_x.cc, src/ltlvisit/remove_x.hh,
src/ltlvisit/simpfg.cc, src/ltlvisit/simpfg.hh,
src/ltlvisit/simplify.cc, src/ltlvisit/simplify.hh, src/ltlvisit/snf.cc,
src/ltlvisit/snf.hh, src/ltlvisit/unabbrev.cc, src/ltlvisit/unabbrev.hh,
src/parseaut/parseaut.yy, src/ta/taexplicit.cc, src/ta/tgtaexplicit.cc,
src/taalgos/minimize.cc, src/taalgos/tgba2ta.cc, src/tests/bare.test,
src/tests/checkpsl.cc, src/tests/checkta.cc,
src/tests/complementation.cc, src/tests/consterm.cc,
src/tests/emptchk.cc, src/tests/equalsf.cc, src/tests/ikwiad.cc,
src/tests/isop.test, src/tests/kind.cc, src/tests/length.cc,
src/tests/ltldo.test, src/tests/ltlfilt.test, src/tests/ltlgrind.test,
src/tests/ltlprod.cc, src/tests/ltlrel.cc,
src/tests/parse_print_test.cc, src/tests/parseaut.test,
src/tests/parseerr.test, src/tests/randtgba.cc, src/tests/readltl.cc,
src/tests/reduc.cc, src/tests/syntimpl.cc, src/tests/taatgba.cc,
src/tests/tostring.cc, src/tests/twagraph.cc, src/tests/utf8.test,
src/twa/acc.cc, src/twa/bdddict.cc, src/twa/bdddict.hh,
src/twa/bddprint.cc, src/twa/formula2bdd.cc, src/twa/formula2bdd.hh,
src/twa/taatgba.cc, src/twa/taatgba.hh, src/twa/twa.cc, src/twa/twa.hh
src/twa/twagraph.cc, src/twa/twagraph.hh, src/twa/twasafracomplement.cc,
src/twaalgos/compsusp.cc, src/twaalgos/compsusp.hh,
src/twaalgos/dtgbasat.cc, src/twaalgos/hoa.cc, src/twaalgos/lbtt.cc,
src/twaalgos/ltl2taa.cc, src/twaalgos/ltl2taa.hh,
src/twaalgos/ltl2tgba_fm.cc, src/twaalgos/ltl2tgba_fm.hh,
src/twaalgos/minimize.cc, src/twaalgos/minimize.hh,
src/twaalgos/neverclaim.cc, src/twaalgos/postproc.cc,
src/twaalgos/postproc.hh, src/twaalgos/powerset.cc,
src/twaalgos/powerset.hh, src/twaalgos/randomgraph.cc,
src/twaalgos/remprop.cc, src/twaalgos/remprop.hh, src/twaalgos/stats.cc,
src/twaalgos/stats.hh, src/twaalgos/stutter.cc, src/twaalgos/stutter.hh,
src/twaalgos/translate.cc, src/twaalgos/translate.hh,
wrap/python/ajax/spotcgi.in, wrap/python/spot.py,
wrap/python/spot_impl.i, wrap/python/Makefile.am,
wrap/python/tests/automata-io.ipynb, wrap/python/tests/formulas.ipynb,
wrap/python/tests/ltl2tgba.py, wrap/python/tests/ltlparse.py,
wrap/python/tests/ltlsimple.py, wrap/python/tests/randltl.ipynb: Adjust
to use the new interface.
* src/sanity/style.test: Accept more C++11 patterns.
* NEWS: Mention the change.

This implies learning alternative rules for G, and W as well, since
those would use R.

Fixes #103.  Suggested by Joachim Klein.

* src/ltlvisit/unabbrev.cc, src/ltlvisit/unabbrev.hh: Implement the
new rules.
* doc/tl/tl.tex: Document the rules.
* src/tests/unabbrevwm.test: Test them.
* src/bin/ltlfilt.cc, NEWS: Mention that --unabbreviate accepts R.

* src/bin/ltlfilt.cc: Add option --unabbreviate.
* src/tests/ltlfilt.test: Add a test case.
* NEWS: Mention it.

* src/ltlvisit/lunabbrev.cc, src/ltlvisit/lunabbrev.hh,
src/ltlvisit/tunabbrev.cc, src/ltlvisit/tunabbrev.hh,
src/ltlvisit/wmunabbrev.cc, src/ltlvisit/wmunabbrev.hh: Delete.
* src/ltlvisit/unabbrev.cc, src/ltlvisit/unabbrev.hh: New files.
* src/ltlvisit/Makefile.am: Adjust.
* src/ltlvisit/print.cc, src/tests/equalsf.cc, src/tests/Makefile.am,
src/twaalgos/ltl2taa.cc, wrap/python/spot_impl.i, src/bin/ltlfilt.cc:
Adjust callers.
* src/ltlvisit/contain.cc, src/tests/syntimpl.cc: Remove useless
include.
* wrap/python/tests/formulas.ipynb: New test cases.
* doc/tl/tl.tex: Group all rules in a single section.
* NEWS: Mention it.

* src/bin/man/autfilt.x, src/bin/man/dstar2tgba.x,
src/bin/man/ltl2tgba.x, src/bin/man/ltlcross.x,
src/bin/man/ltlgrind.x, src/bin/man/randltl.x, src/bin/man/spot-x.x:
Improve typesetting and cross-references.
* tools/help2man: Adjust to better detect the optional arguments.
Detect options that are not separated from their description by two
spaces.  Argp output some of those.
* tools/man2html.pl: New file.
* Makefile.am: Distribute it.
* src/bin/ltlfilt.cc: Fix description of --define.
* src/bin/ltlgrind.cc: Fix duplicate description for --help and
--version.  Reorder --help output slightly.
* NEWS: Mention the few fixes.

This actually performs three related changes, but separating them
would be quite inconvenient.

1) rename tostring.hh to print.hh a welcome side-effect is that
I could fix several files that included this file for not reason.

2) de-overload some of the to_string functions, and rename them
as follow:

  to_string -> print_psl, print_sere, str_psl, str_sere
  to_utf8_string -> print_utf8_psl, print_utf8_sere,
                    str_utf8_psl, str_utf8_sere
  to_spin_string -> print_spin_ltl, str_spin_ltl
  to_wring_string -> print_wring_ltl, str_wing_ltl
  to_lbt_string -> print_lbt_ltl, str_lbt_ltl
  to_latex_string -> print_latex_psl, str_latex_psl
  to_sclatex_string -> print_sclatex_psl, str_sclatex_psl

Now it is clearer what these functions do, and their restrictions.

3) all those print_* functions now take the stream to write onto
as their first argument.  This fixes #88.

* src/ltlvisit/tostring.cc, src/ltlvisit/tostring.hh: Rename into...
* src/ltlvisit/print.cc, src/ltlvisit/print.hh: ... those, and make
the changes listed above.
* doc/org/tut01.org, src/bin/common_output.cc,
src/bin/common_trans.cc, src/bin/ltl2tgba.cc, src/bin/ltl2tgta.cc,
src/bin/ltlcross.cc, src/bin/ltldo.cc, src/bin/ltlfilt.cc,
src/bin/randltl.cc, src/ltlparse/ltlparse.yy,
src/ltlvisit/Makefile.am, src/ltlvisit/mark.cc,
src/ltlvisit/relabel.cc, src/ltlvisit/simplify.cc,
src/ltlvisit/snf.cc, src/ta/taexplicit.cc, src/ta/tgtaexplicit.cc,
src/taalgos/tgba2ta.cc, src/tests/equalsf.cc, src/tests/ltl2tgba.cc,
src/tests/ltlrel.cc, src/tests/randtgba.cc, src/tests/reduc.cc,
src/tests/syntimpl.cc, src/tests/tostring.cc, src/twa/bdddict.cc,
src/twa/bddprint.cc, src/twa/taatgba.cc, src/twa/taatgba.hh,
src/twa/twagraph.cc, src/twaalgos/compsusp.cc, src/twaalgos/lbtt.cc,
src/twaalgos/ltl2taa.cc, src/twaalgos/ltl2tgba_fm.cc,
src/twaalgos/neverclaim.cc, src/twaalgos/remprop.cc,
src/twaalgos/stats.cc, wrap/python/ajax/spot.in, wrap/python/spot.py,
wrap/python/spot_impl.i: Adjust.

Automatic mass renaming.

* src/tgbaalgos/: Rename as...
* src/twaalgos/: ... this.
* README, configure.ac, iface/ltsmin/modelcheck.cc, src/Makefile.am,
src/bin/autfilt.cc, src/bin/common_aoutput.cc,
src/bin/common_aoutput.hh, src/bin/common_output.hh,
src/bin/common_post.hh, src/bin/dstar2tgba.cc, src/bin/ltl2tgba.cc,
src/bin/ltl2tgta.cc, src/bin/ltlcross.cc, src/bin/ltldo.cc,
src/bin/ltlfilt.cc, src/bin/randaut.cc, src/dstarparse/dra2ba.cc,
src/dstarparse/nra2nba.cc, src/dstarparse/nsa2tgba.cc,
src/graphtest/twagraph.cc, src/kripke/kripkeprint.cc,
src/ltlvisit/contain.cc, src/ltlvisit/contain.hh,
src/ltlvisit/exclusive.cc, src/taalgos/emptinessta.hh,
src/tgbatest/checkpsl.cc, src/tgbatest/checkta.cc,
src/tgbatest/complementation.cc, src/tgbatest/emptchk.cc,
src/tgbatest/ltl2tgba.cc, src/tgbatest/ltlprod.cc,
src/tgbatest/randtgba.cc, src/tgbatest/taatgba.cc, src/twa/twa.cc,
src/twa/twagraph.hh, src/twa/twasafracomplement.cc,
wrap/python/spot_impl.i: Adjust.

* src/bin/ltlfilt.cc: Implement it.
* src/bin/common_output.cc, src/bin/common_output.hh: export the
stream_formula function.
* src/ltltest/ltlfilt.test: Test it.
* src/ltlvisit/relabel.hh: Make it possible to clear the
relabeling map.
* NEWS, doc/org/ltlfilt.org: Mention --define.

* src/ltlvisit/exclusive.cc, src/ltlvisit/exclusive.hh: New files.
* src/ltlvisit/Makefile.am: Add them.
* src/bin/ltlfilt.cc: Implement the --exclusive-ap option.
* NEWS: Mention it.
* src/ltltest/exclusive.test: New file.
* src/ltltest/Makefile.am: Add it.

Thibaud Michaud authored Nov 06, 2014 and Alexandre Duret-Lutz committed Mar 08, 2015

* wrap/python/spot.i: Rename to...
* wrap/python/spot_impl.i: ...this, and import spot_impl from spot.py so
that it is not needed to recompile everything when modifying python
code.
* wrap/python/spot.py: Adding python functions to mirror the
functionalities found in src/bin.
* src/bin/common_r.cc: Move simplification level...
* src/ltlvisit/simplify.hh: ... here as a constructor of
ltl_simplifier_options, to make it available in wrap/python.
* src/bin/ltlfilt.cc: Set simplification level using the new
ltl_simplifier_options constructor.
* src/bin/randltl.cc: Move most of the code...
* src/ltlvisit/randomltl.cc, src/ltlvisit/randomltl.hh: ... here, as a
class named randltlgenerator.
* wrap/python/tests/bddnqueen.py, wrap/python/tests/minato.py: Avoid
calling bdd_init twice by moving 'import spot' after bdd initialization.
* wrap/python/Makefile.am: Rename spot to spot_impl
* wrap/python/tests/Makefile.am: Add ipnbdoctest.py.
* wrap/python/.gitignore: Rename spot.py to spot_impl.py
* src/ltlvisit/tostring.cc: \ttrue and \ffalse should be \top and \bot.
* wrap/python/tests/ipnbdoctest.py: Run code cells of a python notebook
and compare the output to the actual content of the notebook.
* wrap/python/tests/randltl.ipynb: Document and test randltl.
* wrap/python/tests/run.in: Call ipnbdoctest.py to run ipython
notebooks.

* src/bin/autfilt.cc, src/bin/common_aoutput.cc,
src/bin/common_finput.cc, src/bin/common_output.cc,
src/bin/common_post.cc, src/bin/common_setup.cc,
src/bin/common_trans.cc, src/bin/dstar2tgba.cc, src/bin/genltl.cc,
src/bin/ltl2tgba.cc, src/bin/ltl2tgta.cc, src/bin/ltlcross.cc,
src/bin/ltlfilt.cc, src/bin/ltlgrind.cc, src/bin/randaut.cc,
src/bin/randltl.cc: Here.

* src/bin/common_output.cc, src/bin/common_output.hh:
Add count_output.
* src/bin/ltlfilt.cc: Add the --count option.
* src/ltltest/ltlfilt.test: Test it.
* NEWS: Mention it.

* src/bin/common_conv.cc, src/bin/common_conv.hh: New files.
* src/bin/Makefile.am: Add them.
* src/bin/autfilt.cc, src/bin/ltlcross.cc, src/bin/ltlfilt.cc,
src/bin/ltlgrind.cc, src/bin/randaut.cc, src/bin/randltl.cc: Use them.

and adjust it to detect siPSL formulas, as in the paper of Dax et
al. (ATVA'09).  For issue #51.

* src/ltlast/atomic_prop.cc, src/ltlast/binop.cc,
src/ltlast/bunop.cc, src/ltlast/constant.cc, src/ltlast/formula.cc,
src/ltlast/formula.hh, src/ltlast/multop.cc, src/ltlast/unop.cc: Rename
the property, and adjust its computation on siSERE.
* src/ltlvisit/remove_x.cc, src/ltlvisit/simplify.cc,
src/tgbaalgos/stutter.cc: Adjust to new names.
* src/bin/ltlfilt.cc: Add option --syntactic-sutter-invariant.
* src/ltltest/kind.test: Update tests and add some new.

This fixes #44.

* src/bin/ltlfilt.cc: Implement -n/--max-count.
* doc/org/ltlfilt.org, src/tgbatest/randpsl.test: Use it
* NEWS: Document it.

* src/bin/ltlfilt.cc: Remove short option -n for --negate.

This avoid compiler errors about ambiguous calls and make sure we are
calling the intended algorithms everywhere (this wasn't the case).

* src/tgba/tgbaproduct.hh (product, product_at): Rename as...
(otf_product, otf_product_at): ... this.
* iface/ltsmin/modelcheck.cc, src/bin/autfilt.cc, src/bin/ltlfilt.cc,
src/tgbaalgos/minimize.cc, src/tgbaalgos/powerset.cc,
src/tgbatest/ltl2tgba.cc, src/tgbatest/checkpsl.cc,
src/tgbatest/complementation.cc, src/tgbatest/ltlprod.cc: Adjust
callers.

the existing -q/--quiet option is renamed to --ignore-errors

* src/bin/ltlfilt.cc: Adjust option.
* src/bin/common_output.cc, src/bin/common_output.hh: Add a
quiet_output.
* bench/dtgbasat/prepare.sh: Rename -q to --ignore-errors..
* src/ltltest/remove_x.test: Use -q.
* NEWS: Mention this change.

* src/ltltest/ltlfilt.test: Add more tests.
* src/ltltest/stutter.test: New test.
* src/ltltest/Makefile.am: Adjust.
* src/bin/ltlfilt.cc: Catch std::runtime_error.
* src/tgba/tgbasl.hh (make_tgbasl): New function.
* src/tgba/tgbagraph.hh (make_tgba_graph): Add another overload.
* src/tgbaalgos/stutter_invariance.cc,
src/tgbaalgos/stutter_invariance.hh: Take the algorithm version as an
optional integer, and call getenv() only once.
* bench/stutter/stutter_invariance_randomgraph.cc,
bench/stutter/stutter_invariance_formulas.cc: Simplify using the
above functions.

Thibaud Michaud authored Oct 01, 2014 and Alexandre Duret-Lutz committed Nov 14, 2014

* src/tgbaalgos/closure.cc, src/tgbaalgos/closure.hh:
Add closure function.
* src/tgbaalgos/stutterize.cc, src/tgbaalgos/stutterize.hh:
Add two implementations of "self-loopize" function.
* src/tgbaalgos/Makefile.am: Add them.
* src/tgba/tgbasl.cc, src/tgba/tgbasl.hh: On-the-fly implementation of
self-loopize.
* src/tgba/Makefile.am: Add it.
* src/tgbatest/ltl2tgba.cc, src/tgbatest/stutter_invariant.test: Test
closure and sl.
* src/tgbatest/Makefile.am: Adjust.
* src/bin/ltlfilt.cc: Modify stutter-invariant option to use
automaton-based checking rather than syntactic-based checking.
* src/ltlvisit/remove_x.cc, src/ltlvisit/remove_x.hh:
Remove is_stutter_insensitive function.
* src/tgbaalgos/stutter_invariance.cc,
src/tgbaalgos/stutter_invariance.hh: Check if a formula is
stutter-invariant using closure and sl.
* wrap/python/spot.i: Add closure and sl bindings.
* bench/stutter/stutter_invariance_formulas.cc: Generate benchmarks from
given formulas.
* bench/stutter/stutter_invariance_randomgraph.cc: Generate benchmarks
from random automata.
* bench/stutter/Makefile.am: Add them.
* configure.ac: Add bench/stutter/Makefile.
* bench/Makefile.am: Add stutter subdirectory.
* README: Document bench/stutter directory.

Thibaud Michaud authored Oct 16, 2014 and Alexandre Duret-Lutz committed Nov 14, 2014

* src/bin/ltlfilt.cc: Add --ap=N option.

A type such as 'const tgba_digraph*' and 'tgba_digraph*' are replaced
by 'const_tgba_digraph_ptr' and 'tgba_digraph_ptr'.  Additionally 'new
tgba_digraph(...)' is replaced by 'make_tgba_digraph(...)'.

This convention is followed by all automata types. Those smart
pointers should normally be passed by const reference as input of
function to avoid the atomic increments/decrements, but I probably
missed a few, as this huge patch took me nearly 12h.

* src/kripke/fwd.hh, src/tgba/fwd.hh: New files.
* src/kripke/Makefile.am, src/tgba/Makefile.am: Adjust.
* iface/dve2/dve2.cc, iface/dve2/dve2.hh, iface/dve2/dve2check.cc,
src/bin/common_output.hh, src/bin/dstar2tgba.cc,
src/bin/ltl2tgba.cc, src/bin/ltl2tgta.cc, src/bin/ltlcross.cc,
src/bin/ltlfilt.cc, src/dstarparse/dra2ba.cc,
src/dstarparse/dstar2tgba.cc, src/dstarparse/dstarparse.yy,
src/dstarparse/nra2nba.cc, src/dstarparse/nsa2tgba.cc,
src/dstarparse/public.hh, src/graphtest/tgbagraph.cc,
src/kripke/fairkripke.hh, src/kripke/kripke.hh,
src/kripke/kripkeexplicit.cc, src/kripke/kripkeexplicit.hh,
src/kripke/kripkeprint.cc, src/kripke/kripkeprint.hh,
src/kripkeparse/kripkeparse.yy, src/kripkeparse/public.hh,
src/kripketest/parse_print_test.cc, src/ltlvisit/apcollect.cc,
src/ltlvisit/apcollect.hh, src/ltlvisit/contain.cc,
src/ltlvisit/contain.hh, src/neverparse/neverclaimparse.yy,
src/neverparse/public.hh, src/priv/accmap.hh,
src/priv/countstates.cc, src/priv/countstates.hh, src/saba/saba.hh,
src/saba/sabacomplementtgba.cc, src/saba/sabacomplementtgba.hh,
src/sabaalgos/sabadotty.cc, src/sabaalgos/sabadotty.hh,
src/sabaalgos/sabareachiter.cc, src/sabaalgos/sabareachiter.hh,
src/sabatest/sabacomplementtgba.cc, src/ta/ta.hh,
src/ta/taexplicit.cc, src/ta/taexplicit.hh, src/ta/taproduct.cc,
src/ta/taproduct.hh, src/ta/tgta.hh, src/ta/tgtaexplicit.cc,
src/ta/tgtaexplicit.hh, src/ta/tgtaproduct.cc,
src/ta/tgtaproduct.hh, src/taalgos/dotty.cc, src/taalgos/dotty.hh,
src/taalgos/emptinessta.cc, src/taalgos/emptinessta.hh,
src/taalgos/minimize.cc, src/taalgos/minimize.hh,
src/taalgos/reachiter.cc, src/taalgos/reachiter.hh,
src/taalgos/statessetbuilder.cc, src/taalgos/statessetbuilder.hh,
src/taalgos/stats.cc, src/taalgos/stats.hh, src/taalgos/tgba2ta.cc,
src/taalgos/tgba2ta.hh, src/tgba/bdddict.cc, src/tgba/bdddict.hh,
src/tgba/formula2bdd.hh, src/tgba/futurecondcol.cc,
src/tgba/futurecondcol.hh, src/tgba/taatgba.hh, src/tgba/tgba.cc,
src/tgba/tgba.hh, src/tgba/tgbagraph.hh,
src/tgba/tgbakvcomplement.cc, src/tgba/tgbakvcomplement.hh,
src/tgba/tgbamask.cc, src/tgba/tgbamask.hh, src/tgba/tgbaproduct.cc,
src/tgba/tgbaproduct.hh, src/tgba/tgbaproxy.cc,
src/tgba/tgbaproxy.hh, src/tgba/tgbasafracomplement.cc,
src/tgba/tgbasafracomplement.hh, src/tgba/tgbascc.cc,
src/tgba/tgbascc.hh, src/tgba/tgbasgba.cc, src/tgba/tgbasgba.hh,
src/tgba/wdbacomp.cc, src/tgba/wdbacomp.hh,
src/tgbaalgos/bfssteps.cc, src/tgbaalgos/bfssteps.hh,
src/tgbaalgos/complete.cc, src/tgbaalgos/complete.hh,
src/tgbaalgos/compsusp.cc, src/tgbaalgos/compsusp.hh,
src/tgbaalgos/cycles.hh, src/tgbaalgos/degen.cc,
src/tgbaalgos/degen.hh, src/tgbaalgos/dotty.cc,
src/tgbaalgos/dotty.hh, src/tgbaalgos/dottydec.cc,
src/tgbaalgos/dottydec.hh, src/tgbaalgos/dtbasat.cc,
src/tgbaalgos/dtbasat.hh, src/tgbaalgos/dtgbacomp.cc,
src/tgbaalgos/dtgbacomp.hh, src/tgbaalgos/dtgbasat.cc,
src/tgbaalgos/dtgbasat.hh, src/tgbaalgos/dupexp.cc,
src/tgbaalgos/dupexp.hh, src/tgbaalgos/emptiness.cc,
src/tgbaalgos/emptiness.hh, src/tgbaalgos/gtec/gtec.cc,
src/tgbaalgos/gtec/gtec.hh, src/tgbaalgos/gtec/status.cc,
src/tgbaalgos/gtec/status.hh, src/tgbaalgos/gv04.cc,
src/tgbaalgos/gv04.hh, src/tgbaalgos/isdet.cc,
src/tgbaalgos/isdet.hh, src/tgbaalgos/isweakscc.cc,
src/tgbaalgos/lbtt.cc, src/tgbaalgos/lbtt.hh,
src/tgbaalgos/ltl2taa.cc, src/tgbaalgos/ltl2taa.hh,
src/tgbaalgos/ltl2tgba_fm.cc, src/tgbaalgos/ltl2tgba_fm.hh,
src/tgbaalgos/magic.cc, src/tgbaalgos/magic.hh,
src/tgbaalgos/minimize.cc, src/tgbaalgos/minimize.hh,
src/tgbaalgos/ndfs_result.hxx, src/tgbaalgos/neverclaim.cc,
src/tgbaalgos/neverclaim.hh, src/tgbaalgos/postproc.cc,
src/tgbaalgos/postproc.hh, src/tgbaalgos/powerset.cc,
src/tgbaalgos/powerset.hh, src/tgbaalgos/projrun.cc,
src/tgbaalgos/projrun.hh, src/tgbaalgos/randomgraph.cc,
src/tgbaalgos/randomgraph.hh, src/tgbaalgos/reachiter.cc,
src/tgbaalgos/reachiter.hh, src/tgbaalgos/reducerun.cc,
src/tgbaalgos/reducerun.hh, src/tgbaalgos/replayrun.cc,
src/tgbaalgos/replayrun.hh, src/tgbaalgos/rundotdec.cc,
src/tgbaalgos/rundotdec.hh, src/tgbaalgos/safety.cc,
src/tgbaalgos/safety.hh, src/tgbaalgos/save.cc,
src/tgbaalgos/save.hh, src/tgbaalgos/scc.cc, src/tgbaalgos/scc.hh,
src/tgbaalgos/sccfilter.cc, src/tgbaalgos/sccfilter.hh,
src/tgbaalgos/sccinfo.cc, src/tgbaalgos/sccinfo.hh,
src/tgbaalgos/se05.cc, src/tgbaalgos/se05.hh,
src/tgbaalgos/simulation.cc, src/tgbaalgos/simulation.hh,
src/tgbaalgos/stats.cc, src/tgbaalgos/stats.hh,
src/tgbaalgos/stripacc.cc, src/tgbaalgos/stripacc.hh,
src/tgbaalgos/tau03.cc, src/tgbaalgos/tau03.hh,
src/tgbaalgos/tau03opt.cc, src/tgbaalgos/tau03opt.hh,
src/tgbaalgos/translate.cc, src/tgbaalgos/translate.hh,
src/tgbaparse/public.hh, src/tgbaparse/tgbaparse.yy,
src/tgbatest/complementation.cc, src/tgbatest/explprod.cc,
src/tgbatest/ltl2tgba.cc, src/tgbatest/ltlprod.cc,
src/tgbatest/maskacc.cc, src/tgbatest/powerset.cc,
src/tgbatest/randtgba.cc, src/tgbatest/taatgba.cc,
src/tgbatest/tgbaread.cc, src/tgbatest/tripprod.cc,
wrap/python/ajax/spot.in, wrap/python/spot.i,
wrap/python/tests/interdep.py: Use shared pointers for automata.

This is a huge patch.  tgba_digraph are equiped with some boolean
properties that can be used to indicate whether they represent SBA
(and will carry more informations later).  All algorithms that produce
or use sba_explicit_* automata are changed to use tgba_digraph.
postproc has been rewritten using only tgba_digraph, and this required
changing the return types of many algorithms from tgba* to
tgba_digraph*.

* src/bin/dstar2tgba.cc, src/bin/ltlfilt.cc, src/dstarparse/dra2ba.cc,
src/dstarparse/dstar2tgba.cc, src/dstarparse/nra2nba.cc,
src/dstarparse/nsa2tgba.cc, src/dstarparse/public.hh,
src/tgba/tgbagraph.hh, src/tgba/tgbasafracomplement.cc,
src/tgbaalgos/compsusp.cc, src/tgbaalgos/compsusp.hh,
src/tgbaalgos/degen.cc, src/tgbaalgos/degen.hh,
src/tgbaalgos/dotty.cc, src/tgbaalgos/minimize.cc,
src/tgbaalgos/minimize.hh, src/tgbaalgos/postproc.cc,
src/tgbaalgos/postproc.hh, src/tgbaalgos/sccfilter.cc,
src/tgbaalgos/sccinfo.cc, src/tgbaalgos/stripacc.cc,
src/tgbaalgos/stripacc.hh, src/tgbaalgos/translate.cc,
src/tgbaalgos/translate.hh, src/tgbatest/ltl2tgba.cc,
wrap/python/spot.i: Update.

This of course concerns push_back and push_front as well.

* src/bin/common_finput.cc, src/bin/dstar2tgba.cc, src/bin/ltl2tgba.cc,
src/bin/ltl2tgta.cc, src/bin/ltlcross.cc, src/bin/ltlfilt.cc,
src/dstarparse/dstarparse.yy, src/kripkeparse/kripkeparse.yy,
src/ltlast/formula.cc, src/ltlparse/ltlparse.yy, src/misc/minato.cc,
src/neverparse/neverclaimparse.yy, src/priv/bddalloc.cc, src/ta/ta.cc,
src/taalgos/emptinessta.cc, src/tgba/taatgba.cc,
src/tgbaalgos/gtec/gtec.cc, src/tgbaalgos/gtec/sccstack.cc,
src/tgbaalgos/magic.cc, src/tgbaalgos/ndfs_result.hxx,
src/tgbaalgos/rundotdec.cc, src/tgbaalgos/scc.cc, src/tgbaalgos/se05.cc,
src/tgbaalgos/simulation.cc, src/tgbaalgos/tau03.cc,
src/tgbaalgos/tau03opt.cc, src/tgbaparse/tgbaparse.yy: Use emplace
to make the code less verbose and avoid creating temporaries.

* bench/scc-stats/stats.cc, bench/split-product/cutscc.cc,
iface/gspn/ssp.cc, src/bin/ltlcross.cc, src/bin/ltlfilt.cc,
src/bin/randltl.cc, src/dstarparse/nsa2tgba.cc, src/ltlast/formula.hh,
src/ltlast/nfa.hh, src/ltlvisit/contain.hh, src/ltlvisit/dotty.cc,
src/ltlvisit/mark.hh, src/ltlvisit/relabel.cc, src/ltlvisit/relabel.hh,
src/ltlvisit/simplify.cc, src/ltlvisit/snf.hh, src/misc/hash.hh,
src/misc/mspool.hh, src/priv/acccompl.hh, src/priv/accconv.hh,
src/saba/explicitstateconjunction.hh, src/saba/sabastate.hh,
src/sabaalgos/sabareachiter.hh, src/sanity/style.test,
src/ta/taexplicit.cc, src/ta/taexplicit.hh, src/taalgos/emptinessta.cc,
src/taalgos/minimize.cc, src/taalgos/reachiter.hh, src/tgba/state.hh,
src/tgba/taatgba.hh, src/tgba/tgbabddconcretefactory.hh,
src/tgba/tgbaexplicit.hh, src/tgba/tgbakvcomplement.cc,
src/tgba/tgbasafracomplement.cc, src/tgba/tgbatba.cc,
src/tgba/tgbatba.hh, src/tgbaalgos/cutscc.cc, src/tgbaalgos/cycles.hh,
src/tgbaalgos/degen.cc, src/tgbaalgos/dtbasat.cc,
src/tgbaalgos/dtgbasat.cc, src/tgbaalgos/eltl2tgba_lacim.cc,
src/tgbaalgos/emptiness.cc, src/tgbaalgos/gtec/explscc.hh,
src/tgbaalgos/gtec/nsheap.hh, src/tgbaalgos/gv04.cc,
src/tgbaalgos/ltl2tgba_fm.cc, src/tgbaalgos/magic.cc,
src/tgbaalgos/minimize.cc, src/tgbaalgos/ndfs_result.hxx,
src/tgbaalgos/powerset.hh, src/tgbaalgos/randomgraph.cc,
src/tgbaalgos/reachiter.hh, src/tgbaalgos/replayrun.cc,
src/tgbaalgos/safety.cc, src/tgbaalgos/scc.hh, src/tgbaalgos/se05.cc,
src/tgbaalgos/simulation.cc, src/tgbaalgos/tau03.cc,
src/tgbaalgos/tau03opt.cc: Adjust code.
* src/sanity/style.test: Remove check.

* src/bin/common_output.cc, src/bin/common_output.hh:
(output_formula_checked, aut_stat_printer): New.
* src/bin/genltl.cc, src/bin/randltl.cc, src/bin/ltlfilt.cc: Call
output_formula_checked() instead of output_formula().
* src/bin/ltl2tgba.cc: Use aut_stat_printer and add option --csv-escape.
* doc/org/csv.org: New file to document CSV I/O.
* doc/Makefile.am: Add it.
* doc/org/ioltl.org, doc/org/ltlfilt.org, doc/org/ltl2tgba.org,
doc/org/tools.org: Link to csv.org

* NEWS: Mention it.
* src/bin/common_finput.cc, src/bin/common_finput.hh: Implement it.
* src/bin/common_output.cc, src/bin/common_output.hh: Add the %< and
%> escapes.
* src/bin/ltlfilt.cc: Connect %< and %> to the
prefix andsuffix of the input, and document them.
* src/tgbatest/det.test, src/tgbatest/nondet.test: Simplify these
tests that read CSV files.

* src/ltlast/multop.cc, src/ltlast/multop.hh (multop::boolean_operands,
multop::boolean_count): New methods.
* src/ltlvisit/relabel.cc, src/ltlvisit/relabel.hh
(relabel): Take an optional relabeling_map as parameter.
(relabel_bse): New.
* src/ltltest/ltlrel.test, src/ltltest/ltlrel.cc: New files.
* src/ltltest/Makefile.am: Add them.
* src/bin/ltlfilt.cc: Add option --relabel-bool.
* src/ltltest/ltlfilt.test: Test it.
* NEWS: Mention it.
* doc/org/ltlfilt.org: Illustrate it.

* src/bin/common_output.cc: Add option --format and implement
it.
* src/bin/ltlfilt.cc, src/bin/randltl.cc: Document the
supported %-sequences.
* src/bin/genltl.cc: Document the %-sequences, and supply
the name of the pattern to output_formula().
* doc/org/genltl.org, doc/org/ioltl.org, doc/org/ltlfilt.org,
NEWS: Document it.
* src/ltltest/latex.test: Use it.

* src/bin/ltlfilt.cc: Handle --universal and --eventual.  Match
only LTL formulas with --stutter-invariant.
* src/ltltest/ltlfilt.test: New file.
* src/ltltest/Makefile.am (TESTS): Add it.
* NEWS: Mention these bug fixes.

* src/bin/ltlfilt.cc: Add options --remove-x and --stutter-invariant.
* src/ltlvisit/remove_x.cc, src/ltlvisit/remove_x.hh: New files.
* src/ltlvisit/Makefile.am: Add them.
* src/ltltest/remove_x.test: New file.
* src/ltltest/Makefile.am: Add it.
* NEWS: Mention the new algorithms.

* src/ltlvisit/simplify.hh (ltl_simplifier_options): add
a boolean_to_isop option
(ltl_simplifier::boolean_to_isop): New method.
* src/ltlvisit/simplify.cc: Implement these.
* src/bin/ltlfilt.cc: Add a --boolean-to-isop option.
* src/ltltest/isop.test: New file.
* src/ltltest/Makefile.am: Add it.
* NEWS: Mention it.

In particular, this get rid of the ugly -? option that argp adds by
default, and we also remove -V so that we can use it for something
else later.

* src/bin/common_setup.cc, src/bin/common_setup.hh (misc_argp):
Provide support for --help/--version/--usage output, replacing argp's
default builting version.
* src/bin/genltl.cc, src/bin/ltl2tgba.cc, src/bin/ltl2tgta.cc,
src/bin/ltlcheck.cc, src/bin/ltlfilt.cc, src/bin/randltl.cc:
Call argp_parse() with ARGP_NO_HELP, and use misc_argp instead.

* src/bin/ltl2tgba.cc, src/bin/ltl2tgta.cc: Destroy the translated
formulas.
* src/bin/ltlcheck.cc, src/bin/ltlfilt.cc: Free the unicity table on
exit.