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.
This fix recent failures observed on arch linux because
it uses newer versions of graphviz and Python.
* tests/python/ipnbdoctest.py (sanitize): More substitutions.
Jupyter 4.2 just landed in Debian unstable, so we have a few failures
because of all the renamings.
* tests/python/ipnbdoctest.py: Adjust imports for Jupyter 4.2.
* python/spot/ltsmin.i: New file.
* python/Makefile.am: Add it.
* python/spot/impl.i: Add bindings for kripke and fair_kripke.
* tests/python/ltsmin.ipynb: New file.
* tests/Makefile.am, doc/org/tut.org: Add it.
* tests/python/ipnbdoctest.py: Make it possible for notebook
to exit(77).
* debian/control: Make the Python package dependent
on libspotltsmin0.
* python/spot/__init__.py: Typo.
