* 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.