Fixes#153.
* spot/twa/twa.cc, spot/twa/twa.hh: Add the methods.
* bin/autfilt.cc, bin/common_aoutput.hh, bin/ltlcross.cc,
tests/python/highlighting.ipynb, tests/python/word.ipynb: Use
them to simplify the code.
* NEWS: Mention them.
* spot/twa/twa.cc, spot/twa/twa.hh: Add a way to
remove named properties.
* spot/twa/twagraph.cc: Clear highlight-edges on operations
that reorder the edge vector.
* spot/twaalgos/randomize.cc, spot/twaalgos/randomize.hh:
Preserve highlighted state, but not highlighted edges.
* spot/twaalgos/hoa.cc: Adjust output of highlight-edge
when the edges are not stored in order.
* tests/core/readsave.test, tests/core/tgbagraph.test,
tests/core/twagraph.cc: More test cases.
Also introduce twa::unregister_ap() and twa_graph::remove_unused_ap()
so that the methods where this behavior is expected can be fixed.
And fix ltsmin::kripke() which did not register APs.
Part of #170.
* spot/twaalgos/hoa.cc: Use apvars() to print all registerd APs.
Throw an exception when printing automata using unregistered APs.
* spot/ltsmin/ltsmin.cc: Call register_ap().
* spot/twa/twa.cc, spot/twa/twa.hh, spot/twa/twagraph.cc,
spot/twa/twagraph.hh (twa::unregister_ap, twa_graph::remove_unused_ap):
New methods.
* spot/tl/exclusive.cc, spot/twaalgos/postproc.cc,
spot/twaalgos/remprop.cc, spot/twaalgos/relabel.cc: Use them.
* tests/core/maskacc.test, tests/core/maskkeep.test,
tests/core/strength.test: Adjust expected results.
* NEWS: Mention those changes.
* NEWS: Mention the change.
* src/: Rename as ...
* spot/: ... this, adjust all headers to include <spot/...> instead of
"...", and adjust all Makefile.am to search headers from the top-level
directory.
* HACKING: Add conventions about #include.
* spot/sanity/style.test: Add a few more grep to catch cases
that do not follow these conventions.
* .gitignore, Makefile.am, README, bench/stutter/Makefile.am,
bench/stutter/stutter_invariance_formulas.cc,
bench/stutter/stutter_invariance_randomgraph.cc, configure.ac,
debian/rules, doc/Doxyfile.in, doc/Makefile.am,
doc/org/.dir-locals.el.in, doc/org/g++wrap.in, doc/org/init.el.in,
doc/org/tut01.org, doc/org/tut02.org, doc/org/tut03.org,
doc/org/tut10.org, doc/org/tut20.org, doc/org/tut21.org,
doc/org/tut22.org, doc/org/tut30.org, iface/ltsmin/Makefile.am,
iface/ltsmin/kripke.test, iface/ltsmin/ltsmin.cc,
iface/ltsmin/ltsmin.hh, iface/ltsmin/modelcheck.cc,
wrap/python/Makefile.am, wrap/python/ajax/spotcgi.in,
wrap/python/spot_impl.i, wrap/python/tests/ltl2tgba.py,
wrap/python/tests/randgen.py, wrap/python/tests/run.in: Adjust.
