* spot/twaalgos/dot.cc, spot/twaalgos/hoa.cc: If a Kripke
structure is passed, automatically enable the "k" option.
* tests/core/parse_print_test.cc, tests/ltsmin/modelcheck.cc,
tests/python/ltsmin.ipynb: Remove the explicit use of "k".
* NEWS: Mention the change.
* spot/ltsmin/ltsmin.cc, spot/ltsmin/ltsmin.hh: Split load_ltsmin() into
ltsmin_model::load() and ltsmin_model::kripke(). Report errors using
exceptions instead of on std::cerr.
* python/spot/ltsmin.i: Deal with exceptions.
* tests/ltsmin/modelcheck.cc, tests/python/ltsmin.ipynb: Adjust.