* spot/twaalgos/contains.hh, spot/twaalgos/contains.cc
(containment_select_version): New function.
(contains): Use it.
* spot/twa/twa.cc (exclusive_word): Likewise.
* bin/autfilt.cc (--included-in): Adjust to use forq depending
on containement_select_version.
* bin/man/spot-x.x: Adjust documentation of
CONTAINMENT_SELECT_VERSION.
* tests/core/included.test, tests/python/forq_contains.py: Add more
tests.
* NEWS: Mention the new feature.
* spot/twaalgos/postproc.cc, spot/twaalgos/postproc.hh: Introduce a
merge-states-min option.
* bin/spot-x.cc: Document it.
* spot/gen/automata.cc, spot/gen/automata.hh, bin/genaut.cc: Add
option to generate cyclist test cases.
* NEWS: Document the above.
* tests/core/included.test: Add test cases that used to be too slow.