* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtbasat.hh,
src/tgbaalgos/dtgbasat.cc, src/tgbaalgos/dtgbasat.hh: Use tgba_digraph
and modernize syntax slightly.

* src/tgbaalgos/dtgbasat.cc, src/tgbaalgos/eltl2tgba_lacim.cc,
src/tgbaalgos/simulation.cc, src/tgbaalgos/tau03opt.cc: Fix
cases where bddtrue and bddfalse where used in a ternary operator.
* src/sanity/style.test: Allow bdd_true()/bdd_false() to be
used in ternary operators.

* src/sanity/style.test: Add a test.
* iface/dve2/dve2.cc, iface/dve2/dve2check.cc, src/bin/common_output.cc,
src/bin/dstar2tgba.cc, src/bin/ltl2tgba.cc, src/bin/ltlcross.cc,
src/dstarparse/dra2ba.cc, src/dstarparse/fmterror.cc,
src/dstarparse/nsa2tgba.cc, src/kripke/kripkeprint.cc,
src/kripkeparse/fmterror.cc, src/ltlast/atomic_prop.cc,
src/ltlast/bunop.cc, src/ltltest/ltlrel.cc, src/ltltest/reduc.cc,
src/ltltest/syntimpl.cc, src/ltlvisit/dotty.cc, src/ltlvisit/lbt.cc,
src/ltlvisit/randomltl.cc, src/ltlvisit/relabel.cc,
src/ltlvisit/simplify.cc, src/ltlvisit/tostring.cc, src/misc/bitvect.cc,
src/misc/optionmap.cc, src/misc/timer.cc, src/neverparse/fmterror.cc,
src/priv/freelist.cc, src/saba/sabacomplementtgba.cc,
src/sabaalgos/sabadotty.cc, src/taalgos/dotty.cc,
src/taalgos/minimize.cc, src/tgba/bdddict.cc, src/tgba/bddprint.cc,
src/tgba/futurecondcol.cc, src/tgba/taatgba.hh,
src/tgba/tgbakvcomplement.cc, src/tgba/tgbasafracomplement.cc,
src/tgbaalgos/compsusp.cc, src/tgbaalgos/cycles.cc,
src/tgbaalgos/dotty.cc, src/tgbaalgos/dtbasat.cc,
src/tgbaalgos/dtgbasat.cc, src/tgbaalgos/emptiness.cc,
src/tgbaalgos/gtec/gtec.cc, src/tgbaalgos/gv04.cc,
src/tgbaalgos/lbtt.cc, src/tgbaalgos/ltl2tgba_fm.cc,
src/tgbaalgos/minimize.cc, src/tgbaalgos/neverclaim.cc,
src/tgbaalgos/powerset.cc, src/tgbaalgos/replayrun.cc,
src/tgbaalgos/save.cc, src/tgbaalgos/scc.cc, src/tgbaalgos/sccfilter.cc,
src/tgbaalgos/weight.cc, src/tgbaalgos/word.cc,
src/tgbaparse/fmterror.cc, src/tgbatest/bitvect.cc,
src/tgbatest/complementation.cc, src/tgbatest/intvcmp2.cc,
src/tgbatest/intvcomp.cc, src/tgbatest/ltl2tgba.cc,
src/tgbatest/randtgba.cc: Replace << "c" by << 'c' when
appropriate.

Instead of "delete iter;" we now do "aut->release_iter(iter);" to
give the iterator back to the automaton.  The TGBA classes now
reuse a previously returned tgba_succ_iterator to answer a succ_iter()
call, therefore avoiding (1) memory allocation, as well as (2) vtable
and other constant member initialization.

* src/tgba/tgba.hh, src/tgba/tgba.cc (release_iter, iter_cache_):
Implement a release_iter() that stores the released iterator
in iter_cache_.
* src/tgba/succiter.hh (internal::succ_iterable): Move...
* src/tgba/tgba.hh (tgba::succ_iterable): ... here. And use
release_iter().

* iface/dve2/dve2.cc, src/kripke/kripke.cc, src/kripke/kripke.hh,
src/tgba/succiterconcrete.cc, src/tgba/succiterconcrete.hh,
src/tgba/taatgba.hh, src/tgba/tgbabddconcrete.cc,
src/tgba/tgbaexplicit.hh, src/tgba/tgbamask.cc, src/tgba/tgbaproduct.cc,
src/tgba/tgbaproxy.cc, src/tgba/tgbascc.cc, src/tgba/tgbatba.cc,
src/tgba/tgbaunion.cc, src/tgba/tgbaunion.hh, src/tgba/wdbacomp.cc,
src/tgbaalgos/bfssteps.cc, src/tgbaalgos/compsusp.cc,
src/tgbaalgos/cycles.cc, src/tgbaalgos/dtbasat.cc,
src/tgbaalgos/dtgbasat.cc, src/tgbaalgos/gtec/gtec.cc,
src/tgbaalgos/gv04.cc, src/tgbaalgos/isweakscc.cc,
src/tgbaalgos/lbtt.cc, src/tgbaalgos/ltl2tgba_fm.cc,
src/tgbaalgos/magic.cc, src/tgbaalgos/ndfs_result.hxx,
src/tgbaalgos/neverclaim.cc, src/tgbaalgos/reachiter.cc,
src/tgbaalgos/replayrun.cc, src/tgbaalgos/safety.cc,
src/tgbaalgos/scc.cc, src/tgbaalgos/se05.cc,
src/tgbaalgos/simulation.cc, src/tgbaalgos/tau03.cc,
src/tgbaalgos/tau03opt.cc: Use release_iter() instead of deleting
iterators, and used recycle iter_cache_ in implementations of
tgba::succ_iter().

* 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/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc: Record
statistics about intermediate automata if SPOT_SATLOG is set to some
filename, and display intermediate automata if SPOT_SATSHOW is set.
* bench/dtgbasat/stat.sh, bench/dtgbasat/stats.sh,
bench/dtgbasat/tabl.pl, bench/dtgbasat/tabl1.pl,
bench/dtgbasat/tabl2.pl, bench/dtgbasat/tabl3.pl,
bench/dtgbasat/tabl4.pl: Gather these extra statistics.

* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc: Compute the
actual number of reachable states in the produced automaton to prepare
the next iteration.

* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc: More debuging
code.

* src/misc/satsolver.hh, src/misc/satsolver.cc: Present
the SAT solver as an object with a stream interface, to
prepare for a better implementation.
* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc:
Adjust to the new interface, removing all the handling
of temporary files.
* src/tgbatest/readsat.cc: Adjust.

* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc: Rewrite the
loops that number the states of the reference automaton so that
they declare CNF variable numbers in the same order as the states
of the automaton.

* src/tgbaalgos/dtgbasat.cc: Here.

Reuse the existing <q1,q1',q1,q1',0,0> instead.

* src/tgbaalgos/dtgbasat.cc: Simplify.

* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc: Here.

* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc: Throw
exceptions on write errors.

* src/misc/satsolver.hh (clause_counter): New class.
* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc: Use it.

* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc: Greatly reduce
the number of clauses and variable by removing any path variable that
reference a reference transition that is not in a SCC.

Thanks to Rüdiger Ehlers for his helpful email.

* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc: Here.

* src/misc/satsolver.cc, src/misc/satsolver.hh (satsolver_get_solution):
New function, that accepts a solution split on multiple 'v ' lines.
* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc (get_solution):
Remove, and adjust existing code to use satsolver_get_solution().
* src/tgbatest/readsat.cc, src/tgbatest/readsat.test: New files.
* src/tgbatest/Makefile.am: Add them.
* src/bin/man/spot-x.x: Mention the SAT competition rules for
the expected input/output format.

* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtbasat.hh:
(dtba_sat_minimize): Split into...
(dtba_sat_synthetize, dtba_sat_minimize): These.
(dtba_sat_minimize_dichotomy): New function.
* src/tgbaalgos/dtgbasat.cc, src/tgbaalgos/dtgbasat.hh
(dtgba_sat_minimize, dtgba_sat_synthetize): Likewise.
* src/tgbatest/ltl2tgba.cc: Adjust to new interface.
* src/tgbaalgos/postproc.cc, src/tgbaalgos/postproc.hh:
Cleanup option processing for SAT options.
* src/tgbatest/satmin.test: Adjust.
* src/bin/spot-x.cc, src/bin/man/spot-x.x, NEWS: Document.

* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtbasat.hh:
Rename dba_sat_minimize to dtba_sat_minimize.
Make it possible to produce state-based automata, and do
not output useless clauses.
* src/tgbaalgos/dtgbasat.cc, src/tgbaalgos/dtgbasat.hh:
likewise, but also add the possibility to set the
target number of states, as in dtba_sat_minimize.
* src/tgbaalgos/postproc.cc, src/tgbaalgos/postproc.hh:
Add new options for state-based computations and
setting acceptance and states number when using
dtgba_sat_minimize().
* src/tgbatest/ltl2tgba.cc: Adjust calls to
dtba_sat_minimize().
* src/tgbatest/satmin.test: Adjust calls.

Uses the value of the SPOT_SATSOLVER environment variable
to decide how to call the SAT solver.

* src/misc/satsolver.cc, src/misc/satsolver.hh: New files.
* src/misc/Makefile.am: Add them.
* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc: Use satsolver().

Joint work with Soheib Baarir.

* src/tgbaalgos/dtgbasat.cc, src/tgbaalgos/dtgbasat.hh: New files.
* src/tgbaalgos/Makefile.am: Add them.
* src/tgbaalgos/postproc.cc, src/tgbaalgos/postproc.hh: Add
a dtgba-sat-minimize option.
* src/tgbatest/ltl2tgba.cc: Add option -RG.
* src/tgbatest/satmin.test: Add more tests.

* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtbasat.hh: New files.
* src/tgbaalgos/Makefile.am: Add them.
* src/tgbatest/ltl2tgba.cc: Add option -RS.