* src/twaalgos/sccfilter.cc (acc_filter_some, acc_filter_all): Merge
into...
(acc_filter_mask): ... this single parametrized class, and only
remove sets that are only used as Inf.
* src/twa/acc.hh: Add missing operator~.
* src/tests/sccsimpl.test: Add test case.
* src/tests/sccdot.test: Adjust.
* NEWS: Mention the bug.

* 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.

* src/twaalgos/dotty.cc: Add an option (e) to force elliptic shape, and
a heuristic to choose between circle and ellipse by default.
* src/bin/common_aoutput.cc, src/bin/dstar2tgba.cc: Document 'e'.
* src/taalgos/dotty.cc: Ignore 'e'.
* wrap/python/spot.py (setup): Do not force circular states.  The
default should be fine.
* src/tests/det.test, src/tests/dstar.test, src/tests/monitor.test,
src/tests/neverclaimread.test, src/tests/readsave.test,
src/tests/sccdot.test, src/tests/tgbagraph.test: Adjust expected
results.
* NEWS: Adjust.

* src/Makefile.am, README, configure.ac: update references.
* src/tgbatest/: rename as...
* src/tests/: ...this!

Because scc_info does not perform a full emptiness check, it is not
always able to tell whether an SCC is accepting if the acceptance
condition use Fin primitives.  This introduce is_rejecting_scc() in
addition to to is_accepting_scc().  Only one of them may be true, but
they can both be false if scc_info has no idea whether the SCC is
accepting.

* src/tgbaalgos/sccinfo.cc, src/tgbaalgos/sccinfo.hh: Implement
is_rejecting_scc().
* src/bin/ltlcross.cc, src/tgba/acc.cc, src/tgba/acc.hh,
src/tgbaalgos/dtgbacomp.cc, src/tgbaalgos/isweakscc.cc,
src/tgbaalgos/remfin.cc, src/tgbaalgos/safety.cc,
src/tgbaalgos/sccfilter.cc: Use it.
* src/tgbaalgos/dotty.cc: Use is_rejecting_scc() and is_accepting_scc()
to color SCCs.
* doc/org/oaut.org: Document the colors used.
* src/tgbatest/neverclaimread.test, src/tgbatest/readsave.test: Adjust
tests.
* src/tgbatest/sccdot.test: New test case.
* src/tgbatest/Makefile.am: Add it.