This is still missing tests.

* src/bin/autfilt.cc: Add a --sat-minimize option.
* src/misc/optionmap.cc, src/misc/optionmap.hh: Allow passing strings.
* src/twa/acc.cc, src/twa/acc.hh: Add helper functions needed
by the SAT-encoder.
* src/twaalgos/complete.hh: Typos.
* src/twaalgos/dtbasat.hh: Adjust comment.
* src/twaalgos/dtgbasat.cc, src/twaalgos/dtgbasat.hh: Generalize
to take the target acceptance as input.
* src/twaalgos/postproc.cc, src/tests/ltl2tgba.cc: Adjust calls.
* src/twaalgos/sbacc.cc, src/twaalgos/sbacc.hh: Don't pass
the pointer by reference.
* src/tests/acc.cc, src/tests/acc.test: More tests
for the acceptance helper function.