based on Thomas Martinez's src/tgbaalgos/tarjan_on_fly.cc and
src/tgbaalgos/tarjan_on_fly.hh former implementation.
* src/tgbaalgos/Makefile.am (libtgbaalgos_la_SOURCES,
tgbaalgos_HEADERS): Add them.
* src/tgbatest/ltl2tgba.cc, src/tgbatest/randtgba.cc: Bind the
new algorithm.
* src/tgbatest/emptchk.test: Test it.