Part of issue #376, reported by Hashim Ali.
* python/spot/impl.i: Add bindings for kripke_graph.
* python/spot/__init__.py (automaton): Add a want_kripke option.
* spot/kripke/kripkegraph.hh: Honnor the "state-names" property
when displaying states.
* spot/twaalgos/hoa.cc: Preserve names of Kripke states.
* tests/python/ltsmin-dve.ipynb: Illustrate all the above.
* NEWS: Mention those changes.
* THANKS: Add Hashim.
* NEWS: Mention the change.
* python/spot/__init__.py: Add _repr_latex_ for twa_word, and
remove __repr__ and __str__ for atomic_prop_set.
* python/spot/impl.i: Implement __repr__ and __str__ for
atomic_prop_set. Fix __repr__ for trival, acc_code, acc_cond,
mark_t. Remove __repr__ for twa_run and twa_word.
* tests/python/acc_cond.ipynb, tests/python/accparse.ipynb,
tests/python/atva16-fig2a.ipynb, tests/python/automata.ipynb,
tests/python/bdditer.py, tests/python/contains.ipynb,
tests/python/gen.ipynb, tests/python/highlighting.ipynb,
tests/python/ltlsimple.py, tests/python/ltsmin-dve.ipynb,
tests/python/product.ipynb, tests/python/relabel.py,
tests/python/satmin.ipynb tests/python/stutter-inv.ipynb,
tests/python/word.ipynb: Adjust test cases.
* tests/python/formulas.ipynb: Add test for atomic_prop_set.
Fixes#311.
* tests/python/ipnbdoctest.py: Adjust to process the new format,
with a lot of inspiration from Vcsn's copy of this file.
* tests/python/_altscc.ipynb, tests/python/_aux.ipynb,
tests/python/acc_cond.ipynb, tests/python/accparse.ipynb,
tests/python/alternation.ipynb, tests/python/atva16-fig2a.ipynb,
tests/python/atva16-fig2b.ipynb, tests/python/automata-io.ipynb,
tests/python/automata.ipynb, tests/python/decompose.ipynb,
tests/python/formulas.ipynb, tests/python/gen.ipynb,
tests/python/highlighting.ipynb, tests/python/ltsmin-dve.ipynb,
tests/python/ltsmin-pml.ipynb, tests/python/parity.ipynb,
tests/python/piperead.ipynb, tests/python/product.ipynb,
tests/python/randaut.ipynb, tests/python/randltl.ipynb,
tests/python/stutter-inv.ipynb, tests/python/testingaut.ipynb,
tests/python/word.ipynb: Upgrade to the new format.
* NEWS: Mention the change.
