Related to issue #351.
* spot/twaalgos/sccfilter.cc: When handling weak automata, we know
they are very-weak if the SCC count is equal to the number of states.
* tests/core/dca2.test, tests/core/monitor.test,
tests/core/parity2.test, tests/core/randomize.test,
tests/core/readsave.test, tests/core/remfin.test,
tests/core/sccsimpl.test, tests/core/wdba2.test,
tests/python/dualize.py, tests/python/remfin.py: Adjust output.
This is adapted from a proposition in a paper by J. Esparza,
J. Křentínský, and S. Sickert, submitted to LICS'18. We should add
proper references to the code and documentation once that paper is
accepted.
* spot/twaalgos/gfguarantee.cc, spot/twaalgos/gfguarantee.hh:
New files.
* spot/twaalgos/Makefile.am, python/spot/impl.i: Add them.
* spot/twa/fwd.hh: Add a forward declaration of bdd_dict_ptr.
* spot/twaalgos/postproc.cc, spot/twaalgos/postproc.hh: Make it
possible to call finalize() from the translator subclass. Constify
all the do_* functions while we are there.
* spot/twaalgos/translate.cc, spot/twaalgos/translate.hh: Add
a "gf-guarantee" option to decide whether to use the new translation.
* bin/spot-x.cc: Document it.
* tests/core/dca2.test, tests/core/genltl.test,
tests/core/ltl2tgba2.test, tests/core/parity2.test,
tests/core/satmin.test, tests/python/automata.ipynb,
tests/python/sbacc.py: Adjust test cases.
* tests/python/except.py: Add a couple more tests.
* 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.
