* spot/twaalgos/cobuchi.cc, spot/twaalgos/cobuchi.hh (to_nca): New
function.
(weak_to_cobuchi): New internal function, used in to_nca and to_dca
when appropriate.
* spot/twaalgos/postproc.cc, spot/twaalgos/postproc.hh: Implement
the CoBuchi option.
* python/spot/__init__.py: Support it in Python.
* bin/common_post.cc: Add support for --buchi.
* bin/autfilt.cc: Remove the --dca option.
* tests/core/dca.test, tests/python/automata.ipynb: Adjust and add
more tests.  In particular, add more complex persistence and
recurrence formulas to the list of dca.test.
* tests/python/dca.test: Adjust and rename to...
* tests/core/dca2.test: ... this.  Add more tests, to the point
that this is now failing, as described in issue #317.
* tests/python/dca.py: Remove.
* tests/Makefile.am: Adjust.

Fixes #316.

* spot/twaalgos/totgba.cc: Fix confusing definition of scc_inf_wo_fin.
* tests/python/streett_totgba2.py: New test case.
* tests/Makefile.am: Add it.
* NEWS: Mention the bug.

We had new failure on MinGW with GCC believing that some pointer
returned by down_cast could be NULL; and the down_cast function was in
the global namespace.

* spot/misc/casts.hh: Rewrite.
* NEWS: Mention the small issues.
* tests/core/ikwiad.cc, tests/core/ngraph.cc: Adjust to use
spot::down_cast instead of down_cast.

* spot/ltsmin/ltsmin.cc: Avoid C-style function casts with
incompatible types.

* spot/misc/bitvect.cc, spot/misc/bitvect.hh, spot/misc/hash.hh,
spot/twa/acc.hh, spot/twaalgos/cobuchi.cc, spot/twaalgos/degen.cc,
spot/twaalgos/determinize.cc, spot/twaalgos/parity.cc,
spot/twaalgos/powerset.cc, spot/twaalgos/product.cc,
spot/twaalgos/stutter.cc, spot/twaalgos/totgba.cc,
spot/twaalgos/toweak.cc: Mark hash function as noexcept to please GCC
snapshot.

* spot/twaalgos/cobuchi.hh, spot/twaalgos/totgba.hh: Here.

* spot/gen/formulas.cc, spot/gen/formulas.hh: Implement
LTL_GF_IMPLIES.
* bin/genltl.cc: Add --gf-implies.
* NEWS: Mention it.
* tests/core/genltl.test: Use it.

* python/spot/impl.i: Bind is_colored().
* python/spot/__init__.py: Add Colored support to postproc.
* tests/python/parity.py: Add a test case.

* spot/twaalgos/postproc.cc, spot/twaalgos/postproc.hh: Add support
for a colored option.
* bin/common_post.cc, bin/common_post.hh bin/autfilt.cc,
bin/ltl2tgba.cc, bin/dstar2tgba.cc: Add support for --colored-parity.
* bin/ltldo.cc: Adjust as well for consistency, even if --parity and
--colored-parity is not used here.
* tests/core/parity2.test: Add tests.
* doc/org/autfilt.org, doc/org/ltl2tgba.org: Add examples.
* NEWS: Mention --colored-parity.

* tests/python/_autparserr.ipynb: New files, containing error
checking code from automata-io.ipynb and piperead.ipynb.
* tests/python/automata-io.ipynb: Remove error checks, and pipe
examples from piperead.ipynb.
* tests/python/piperead.ipynb: Delete.
* tests/python/word.ipynb: Move error checking code...
* tests/python/_word.ipynb: ... in this new file.
* doc/org/tut.org, tests/Makefile.am: Adjust.

Fixes #311.

* tests/python/ipnbdoctest.py: Adjust to process the new format,
with a lot of inspiration from Vcsn's copy of this file.
* tests/python/_altscc.ipynb, tests/python/_aux.ipynb,
tests/python/acc_cond.ipynb, tests/python/accparse.ipynb,
tests/python/alternation.ipynb, tests/python/atva16-fig2a.ipynb,
tests/python/atva16-fig2b.ipynb, tests/python/automata-io.ipynb,
tests/python/automata.ipynb, tests/python/decompose.ipynb,
tests/python/formulas.ipynb, tests/python/gen.ipynb,
tests/python/highlighting.ipynb, tests/python/ltsmin-dve.ipynb,
tests/python/ltsmin-pml.ipynb, tests/python/parity.ipynb,
tests/python/piperead.ipynb, tests/python/product.ipynb,
tests/python/randaut.ipynb, tests/python/randltl.ipynb,
tests/python/stutter-inv.ipynb, tests/python/testingaut.ipynb,
tests/python/word.ipynb: Upgrade to the new format.
* NEWS: Mention the change.

Fixes #314, reported by František Blahoudek.

* bin/ltlcross.cc: Here.
* tests/core/ltlcross3.test: Add new test case.
* NEWS: Mention the bug.

* spot/twaalgos/remfin.cc: Simplify acceptance before trying the
different strategies.
* spot/twaalgos/cleanacc.cc: Skip simplify_complementary_marks_here()
on generalized Büchi.
* tests/core/remfin.test, tests/python/tra2tba.py: Adjust.
* spot/twaalgos/totgba.cc: Simplify the result of Streett->GBA.
* NEWS: Adjust.

Fixes #315.

* spot/twaalgos/cleanacc.cc (simplify_acceptance_here): Do not
compare the first edge against previous_a.
* tests/core/accsimpl.test: New file.
* tests/Makefile.am: Add it.
* NEWS: Mention the bug.

Fixes #309.

* python/spot/__init__.py (twa_word.as_svg, twa_word.show): New
  methods.
* tests/python/word.ipynb: Use them.
* NEWS: Mention them.

* bin/common_setup.cc, debian/copyright: Here.

* spot/twaalgos/parity.cc: Do not throw a pointer to an exception,
throw the exception directly.  Factor all the throwing code in a
function.
* tests/python/parity.py: Add test case.

* python/spot/__init__.py: Here.
* tests/python/parity.py: New file.
* tests/Makefile.am: Add it.

* spot/twaalgos/postproc.hh, spot/twaalgos/postproc.cc: Add parity
  options.
* bin/common_post.cc: Add support for --parity.
* NEWS: Mention it.
* tests/core/parity2.test: New file.
* tests/Makefile.am: Add it.

Reported by František Blahoudek.

* bin/man/ltlcross.x: Remove obsolete paragraph with reference to
columns in_states, in_edges, in_transitions, and in_acc that
were removed in 1.99.3.

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

The issue also exists with determinism.

* tests/core/sbacc.test: New test case.
* spot/twaalgos/sbacc.cc: Fix it.
* NEWS: Update.

Fixes #312, reported by František Blahoudek.

* spot/twaalgos/sbacc.cc: Detect the case were this can happen,
and fix it.
* tests/core/sbacc.test: New test case.
* NEWS: Mention the bug.

Fixes #313, reported by František Blahoudek.

* spot/twaalgos/totgba.cc (to_generalized_buchi): Fix it.
* tests/core/remfin.test: Test it.
* NEWS: Mention it.

The issue also exists with determinism.

* tests/core/sbacc.test: New test case.
* spot/twaalgos/sbacc.cc: Fix it.
* NEWS: Update.

* python/spot/__init__.py: Deal with vectors of bools.
* tests/python/highlighting.ipynb: Test this.

Fixes #312, reported by František Blahoudek.

* spot/twaalgos/sbacc.cc: Detect the case were this can happen,
and fix it.
* tests/core/sbacc.test: New test case.
* NEWS: Mention the bug.

Fixes #313, reported by František Blahoudek.

* spot/twaalgos/totgba.cc (to_generalized_buchi): Fix it.
* tests/core/remfin.test: Test it.
* NEWS: Mention it.

* python/spot/impl.i (get_product_states, set_product_states): New.
* tests/python/product.ipynb: Use it.
* NEWS: Mention it.

* spot/twaalgos/sccinfo.cc: Here.
* tests/python/sccinfo.py: Test it.

* python/spot/__init__.py: Recognize if the input is already a
formula.
* tests/python/formulas.ipynb: Test this.

* spot/twaalgos/stutter.hh, spot/twaalgos/stutter.cc: Introduce
is_stutter_invariant_forward_closed and
make_stutter_invariant_forward_closed_inplace.
* tests/python/stutter-inv.ipynb: Use them.

* configure.ac, NEWS: Update to 2.4.3.dev.