Fixes #72.

* src/tgbaalgos/totgba.cc, src/tgbaalgos/totgba.hh: New files.
* src/tgbaalgos/Makefile.am: Add them.
* src/tgbaalgos/postproc.cc, src/tgbaalgos/postproc.hh: Add
a Generic output type, and call to_generalized_buchi() if
this type is not selected.
* src/tgbatest/remfin.test: Add some tests.
* src/bin/autfilt.cc: Add a --generic option, and set it
by default.