* src/twaalgos/sccinfo.cc, src/twaalgos/sccinfo.hh
(determine_unknown_acceptance): New function to call explicitly
in case one want to know whether the accepting/rejecting status
of all SCCs regardless of the acceptance.
* src/twaalgos/dotty.cc src/twaalgos/sccfilter.cc,
src/twaalgos/sccfilter.hh: Use it.
* src/tests/unambig.test, src/tests/sccdot.test: Add more tests.
* doc/org/oaut.org: Adjust doc for --dot=s, orange is not output
anymore.