* 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#282.
* spot/misc/bddlt.hh (bdd_less_than_stable): New function.
* spot/twa/twagraph.cc (merge_edges): Use it.
* tests/core/genltl.test: Adjust, and add an extra test
for the behavior of #282.
* tests/core/complement.test, tests/core/degenid.test,
tests/core/ltldo.test, tests/core/prodor.test,
tests/core/readsave.test, tests/core/sbacc.test,
tests/python/atva16-fig2a.ipynb, tests/python/automata.ipynb,
tests/python/decompose.ipynb, tests/python/dualize.py,
tests/python/highlighting.ipynb, tests/python/piperead.ipynb,
tests/python/product.ipynb, tests/python/simstate.py,
tests/python/tra2tba.py: Adjust all expected outputs.
* NEWS: Mention the bug.
* spot/twaalgos/tra2tba.cc: Support Rabin like input
* tests/core/tra2tba.cc: Remove C tests
* tests/core/tra2tba.test: Remove C tests
* tests/python/tra2tba.py: Convert C tests to python
* tests/Makefile.am: Remove C tests and add python tests
