* src/tgbaalgos/degen.cc (unicity_table): Move and rename as...
* src/tgba/state.hh (state_unicity_table): ... this.
* src/tgbaalgos/cutscc.cc, src/tgbaalgos/cycles.cc,
src/tgbaalgos/cycles.hh, src/tgbaalgos/minimize.cc,
src/tgbaalgos/powerset.cc, src/tgbaalgos/powerset.hh,
src/tgbaalgos/safety.cc: Use it to simplify existing code.