* src/tgbaalgos/sccfilter.cc, src/tgbaalgos/sccfilter.hh: Rewrite all
composable filters in a way that allow arguments to be passed.
(scc_filter_susp): New function.
* src/tgbaalgos/sccinfo.cc, src/tgbaalgos/sccinfo.hh (scc_ap_support):
New method.
* src/tgbaalgos/compsusp.cc: Adjust to use tgba_digraph, and
call the new scc_filter_susp().