allow scc_filter() and scc_filter_states() on any TωA
Note however that scc_info does not provide a precise accept/reject characterization for SCCs when using Fin acceptance. However whenever it tells that an SCC is rejecting, scc_filter_states() may safely remove it. * src/twaalgos/sccfilter.cc (scc_filter_states): Allow on any TωA. (scc_filter): Only use acceptance simplifications on TGBA. * src/tests/unambig.test: Add a co-Büchi test.