* src/tgba/Makefile.am: Use $(VISIBILITY_CXXFLAGS).
* src/tgba/bdddict.hh, src/tgba/bddprint.hh, src/tgba/formula2bdd.hh,
src/tgba/futurecondcol.hh, src/tgba/state.hh, src/tgba/statebdd.hh,
src/tgba/succiter.hh, src/tgba/succiterconcrete.hh, src/tgba/taatgba.hh,
src/tgba/tgba.hh, src/tgba/tgbabddconcrete.hh,
src/tgba/tgbabddconcretefactory.hh, src/tgba/tgbabddconcreteproduct.hh,
src/tgba/tgbabddcoredata.hh, src/tgba/tgbabddfactory.hh,
src/tgba/tgbaexplicit.hh, src/tgba/tgbakvcomplement.hh,
src/tgba/tgbaproduct.hh, src/tgba/tgbasafracomplement.hh,
src/tgba/tgbascc.hh, src/tgba/tgbasgba.hh, src/tgba/tgbatba.hh,
src/tgba/tgbaunion.hh, src/tgba/wdbacomp.hh: Mark exported symbols with
SPOT_API.
* src/tgba/public.hh: Mark the file as deprecated.
* src/tgbaalgos/cutscc.hh: Adjust.