* src/tgba/tgbagraph.hh: Remove the set_bprop/get_bprop interface.
* src/tgba/tgba.cc, src/tgba/tgba.hh: Add a new interface for
setting/querying/copying the following properties: single_acc_set,
state_based_acc, inherently_weak, deterministic.
* src/dstarparse/dra2ba.cc, src/dstarparse/nra2nba.cc,
src/neverparse/neverclaimparse.yy, src/saba/sabacomplementtgba.cc,
src/tgba/tgbagraph.cc, src/tgbaalgos/degen.cc, src/tgbaalgos/dotty.cc,
src/tgbaalgos/isdet.cc, src/tgbaalgos/lbtt.cc,
src/tgbaalgos/minimize.cc, src/tgbaalgos/neverclaim.cc,
src/tgbaalgos/postproc.cc, src/tgbaalgos/sccfilter.cc,
src/tgbaalgos/simulation.cc, src/tgbatest/degenlskip.test,
src/tgbatest/ltl2tgba.cc: Adjust to the new interface, or use
it to bypass some useless work.
Also generalize the degen-lcache option.
* src/tgbaalgos/postproc.cc, src/tgbaalgos/postproc.hh: Add the option.
* src/bin/spot-x.cc: Document it.
* src/tgbaalgos/degen.cc, src/tgbaalgos/degen.hh: Implement it.
* src/tgbatest/ltlcross2.test: Add a test configuration.
* src/tgbatest/degenlskip.test: New file.
* src/tgbatest/Makefile.am (TESTS): Add degenlskip.test.
