Loosely based on "Complementing Deterministic Büchi Automata in
Polynomial Time", R. P. Kurshan, 1987, J. Comp. Syst. Sci. 35.

* src/tgbaalgos/dbacomp.cc, src/tgbaalgos/dbacomp.hh: New files.
* src/tgbaalgos/Makefile.am: Add them.
* src/tgbatest/ltl2tgba.cc (-DC): New option to test it.