* doc/org/hierarchy.org, doc/org/hierarchy.tex: New files.
* doc/Makefile.am, doc/org/tools.org, NEWS: Add them.

* spot/twaalgos/minimize.cc (minimize_wdba): Diminish the color of
terminal SCCs that are incomplete, as if they had a non-accepting
sink as successor.
* spot/twaalgos/strength.hh, spot/twaalgos/strength.cc
(is_terminal_automaton): Add an option to ignore trivial SCC as we did
before, since it matters for deciding membership to the guarantee
class.
(is_safety_mwdba): Rewrite as ...
(is_safety_automaton): ... generalizating to any acceptance, and
ignoring trivial SCCs.
* bin/ltlfilt.cc, python/ajax/spotcgi.in, spot/tl/hierarchy.cc,
tests/core/ikwiad.cc: Adjust usage of is_terminal_automaton and
is_safety_automaton().
* tests/core/hierarchy.test: Add a problematic formula as test-case.
* NEWS: Mention the bug.

Tools for deciding the class of a formula.

* spot/tl/hierarchy.cc, spot/tl/hierarchy.hh: New files.
* spot/tl/Makefile.am: Add them.
* bin/common_output.cc, bin/common_output.hh: Implement --format=%h.
* tests/core/hierarchy.test: More tests.
* NEWS: Update.

* spot/twaalgos/remfin.cc, spot/twaalgos/remfin.hh
(rabin_to_buchi_maybe): Make this function public.
* bin/ltlfilt.cc: Implement the two options.
* tests/core/hierarchy.test: New file.
* tests/Makefile.am: Add it.
* NEWS: Mention the new options.

* NEWS: Update.
* doc/org/satmin.org: Update satmin page.
* bin/man/spot-x.x: Document SPOT_XCNF and edit SPOT_SATSOLVER.
* bin/spot-x.cc: Update satmin options.
* bin/autfilt.cc: Update satmin related documentations.
* bin/man/autfilt.x: Update autfilt options.

* bin/autfilt.cc: Add that option.
* tests/core/highlightstate.test: Add test.
* NEWS: Update.

* python/spot/impl.i: Add python bindings.
* spot/twaalgos/langmap.cc: Implement algo.
* spot/twaalgos/langmap.hh: Declare algo.
* spot/twaalgos/Makefile.am: Add new files.
* tests/python/langmap.py: Add tests.
* NEWS: Update.

Algorithms that remove transitions can turn a non-deterministic
automaton into a deterministic one, so we need to be able to specify
that determinism can be improved (as opposed to preserved).

* spot/twa/twa.hh (twa::prop_set::improve_det): New attribute.
(twa::prop_keep, twa::prop_copy): Honor it.
* spot/tl/exclusive.cc, spot/twaalgos/alternation.cc,
spot/twaalgos/complete.cc, spot/twaalgos/degen.cc,
spot/twaalgos/determinize.cc, spot/twaalgos/mask.cc,
spot/twaalgos/minimize.cc, spot/twaalgos/remfin.cc,
spot/twaalgos/remprop.cc, spot/twaalgos/sbacc.cc,
spot/twaalgos/sccfilter.cc, spot/twaalgos/simulation.cc,
spot/twaalgos/strength.cc, spot/twaalgos/stutter.cc,
spot/twaalgos/totgba.cc: Adjust calls to prop_keep() and
prop_copy().

* spot/twa/twa.hh (prop_semi_deterministic): New methods.
* spot/parseaut/parseaut.yy, spot/twaalgos/hoa.cc: Add support for the
semi-deterministic property.
* doc/org/concepts.org, doc/org/hoa.org: Document it.
* spot/twaalgos/isdet.cc,
spot/twaalgos/isdet.hh (is_semi_deterministic): New function.
* bin/autfilt.cc: Add --is-semi-deterministic.
* bin/common_aoutput.cc: Add --check=semi-deterministic.
* tests/core/semidet.test: New file.
* tests/Makefile.am: Add it.
* tests/core/parseaut.test, tests/core/readsave.test: Adjust.

* bin/autfilt.cc: Implement --is-alternating.
* tests/core/complete.test: Test it.
* NEWS: Mention it.

* bin/autfilt.cc: Implement --is-very-weak.
* tests/core/strength.test: Test it.
* NEWS: Mention it.

* doc/org/tut23.org, doc/org/tut24.org, doc/org/tut31.org: New files.
* doc/Makefile.am, doc/org/tut.org: Add them.
* doc/org/hoa.org, doc/org/concepts.org: Adjust for alternation support.
* NEWS: Add links.

* spot/twaalgos/postproc.cc: Call remove_alternation().
* tests/core/alternating.test: Additional test.

* bin/ltlcross.cc: Add an alternation-removal pass, and
adjust CSV output.
* doc/org/ltlcross.org: Update.
* tests/core/ltl3dra.test, tests/core/ltl3ba.test: Add more tests.
* tests/Makefile.am: Add tests/core/ltl3ba.test.
* NEWS: Mention it.

* spot/twa/twa.hh: Implement the property.
* spot/parseaut/parseaut.yy, spot/twaalgos/hoa.cc: Add input
and output for it.
* spot/twaalgos/strength.cc,
spot/twaalgos/strength.hh (is_very_weak_automaton): New function.
* tests/core/alternating.test: Add a test for --check=strength
on an alternating automaton.
* tests/core/strength.test, tests/core/parseaut.test: Adjust expected
output.
* NEWS, doc/org/hoa.org, doc/org/concepts.org: Document it.

* NEWS, configure.ac: Set version 2.2.2.dev.

* NEWS, configure.ac, doc/org/setup.org: Update version.

* python/spot/__init__.py (automata): Do not create a session for
every command, this is only needed if automata() is run with a timeout
parameter.
* python/ajax/spotcgi.in: Adjust exclude the main process from
the process group, so that only children are killed on SIGALRM.
* NEWS: Mention the bug.

* python/spot/__init__.py (automata): Do not create a session for
every command, this is only needed if automata() is run with a timeout
parameter.
* python/ajax/spotcgi.in: Adjust exclude the main process from
the process group, so that only children are killed on SIGALRM.
* NEWS: Mention the bug.

* configure.ac: add an option --enable-c++14.
* NEWS: mention the new option.

* spot/twa/twa.cc: is_empty() and accepting_run() now call the new
version of the Couvreur algorithm.

This version has optimization for explicit twa, and also for weak and
terminal (depending on whether an accepting run is requested) automata.

* spot/twaalgos/couvreurnew.hh, spot/twaalgos/couvreurnew.cc,
  spot/twaalgos/Makefile.am: New files for the new algorithm.
* spot/twaalgos/emptiness.cc, tests/core/randtgba.cc:
  Register new algorithm.

Reported by Shufang Zhu.

* spot/tl/ltlf.cc, spot/tl/ltlf.hh: Fix the transltion
and update the comments.
* tests/core/ltlfilt.test: Adjust test cases.
* NEWS: Mention the fix.
* THANKS: Add Shufang Zhu.

Reported by Shufang Zhu.

* spot/tl/ltlf.cc, spot/tl/ltlf.hh: Fix the transltion
and update the comments.
* tests/core/ltlfilt.test: Adjust test cases.
* NEWS: Mention the fix.
* THANKS: Add Shufang Zhu.

Compilation of each header file alone, as a safety check, was removed
when introducing "#pragma once" because we did not have to check for
possible double inclusion.  However we still need to compile each
header to make sure they are self-contained.

* tests/sanity/includes.test: Compile each header.
* tests/run.in: Export various compiler and directory flags.
* spot/twaalgos/emptiness_stats.hh, spot/misc/mspool.hh,
spot/misc/fixpool.hh: Include <spot/misc/common.hh>.
* spot/misc/common.hh: Include <cassert>.
* NEWS: Mention the fixed headers.

Compilation of each header file alone, as a safety check, was removed
when introducing "#pragma once" because we did not have to check for
possible double inclusion.  However we still need to compile each
header to make sure they are self-contained.

* tests/sanity/includes.test: Compile each header.
* tests/run.in: Export various compiler and directory flags.
* spot/twaalgos/emptiness_stats.hh, spot/misc/mspool.hh,
spot/misc/fixpool.hh: Include <spot/misc/common.hh>.
* spot/misc/common.hh: Include <cassert>.
* NEWS: Mention the fixed headers.

* spot/parseaut/parseaut.yy: Add a diagnostic.
* tests/core/parseaut.test: Test it.
* NEWS: Document it.

This should solve issue with the Debian package.

* spot/ltsmin/Makefile.am: Use the LTDLINC, LTDLDEPS and LIBLTDL as
documented.
* NEWS: Mention the fix.

* spot/parseaut/parseaut.yy: Add a diagnostic.
* tests/core/parseaut.test: Test it.
* NEWS: Document it.

* NEWS, spot/twa/twa.hh: Document the change.
* spot/twa/twagraph.hh, spot/kripke/kripkegraph.hh:
  Add an exception in get_init_state_number().
  get_init_state() now calls get_init_state_number().
* spot/twa/twagraph.cc, spot/twaalgos/simulation.cc,
  spot/twaalgos/powerset.cc, spot/twaalgos/complete.cc,
  spot/twaalgos/sccfilter.cc: Remove now useless tests.
* spot/twaalgos/hoa.cc: Remove now useless comment.
* spot/twaalgos/minimize.cc: Never return an automaton with no state.

This should solve issue with the Debian package.

* spot/ltsmin/Makefile.am: Use the LTDLINC, LTDLDEPS and LIBLTDL as
documented.
* NEWS: Mention the fix.

Fix #198.  Reported by Maximilien Colange.

* spot/twaalgos/strength.cc (is_terminal): Test that no accepting
transition lead to a rejecting SCC.
* tests/core/strength.test: Add test case.
* spot/twaalgos/strength.hh, spot/twa/twa.hh, doc/org/concepts.org:
Adjust documentation.
* NEWS: Mention the fix.

Fix #198.  Reported by Maximilien Colange.

* spot/twaalgos/strength.cc (is_terminal): Test that no accepting
transition lead to a rejecting SCC.
* tests/core/strength.test: Add test case.
* spot/twaalgos/strength.hh, spot/twa/twa.hh, doc/org/concepts.org:
Adjust documentation.
* NEWS: Mention the fix.

Reported by František Blahoudek.

* spot/twaalgos/sccfilter.cc: Remove extra print statement.
* NEWS: Mention it.

Reported by František Blahoudek.

* spot/twaalgos/sccfilter.cc: Remove extra print statement.
* NEWS: Mention it.

* NEWS, configure.ac, doc/org/setup.org: Update.