the original automaton has no acceptance condition.
* src/tgba/tgbasgba.cc, src/tgba/tgbasgba.hh: New option:
when the original automaton has no accepting condition, it
explicitly considers that every state is accepting.
* src/tgba/tgbasgba.hh, src/tgba/tgbasgba.hh: Here.
* src/tgbatest/ltl2tgba.cc: New option `-lS' for state-labeled
automata.
* src/tgba/Makefile.am: Adjust and sort files in tgba_HEADERS
and libtgba_la_SOURCES.