* spot/priv/satcommon.cc, spot/priv/satcommon.hh: Make it possible to
set the log file without setting the environment variable. Adjust
print_log to take the input state and print it as a new column.
* spot/twaalgos/dtbasat.cc, spot/twaalgos/dtwasat.cc: Adjust all
calls to print_log. Fix log output for incremental approaches.
Prefer purge_unreachable_states() over stats_reachable(). Do
not call scc_filter() on colored automata.
* spot/twaalgos/dtwasat.hh: Document the new "log" option.
* NEWS: Mention the changes.
* tests/python/satmin.ipynb: New file.
* tests/Makefile.am: Add it.
* doc/org/satmin.org, doc/org/tut.org: Link to it.
* doc/org/satmin.org, bin/man/spot-x.x: Adjust description
of CSV files.
* bench/dtgbasat/gen.py, bench/dtgbasat/tabl.pl,
bench/dtgbasat/tabl1.pl, bench/dtgbasat/tabl2.pl,
bench/dtgbasat/tabl3.pl, bench/dtgbasat/tabl4.pl: Adjust for
the new column.
* spot/misc/satsolver.cc, spot/misc/satsolver.hh (stats): Make it
const.
* python/spot/__init__.py (sat_minimize): Add display_log and
return_log options.
* tests/python/ipnbdoctest.py: Adjust to not compare SAT-minimization
logs as they contain timings.
This is not optimal yet because it still construct a minimal WDBA
internally, but it's better than the previous way to call
minimize_obligation() since it can avoid constructing the minimized
automaton in a few more cases.
* spot/tl/hierarchy.cc, spot/tl/hierarchy.hh: Introduce
is_obligation().
* bin/ltlfilt.cc: Wire it to --obligation.
* spot/twaalgos/minimize.cc: Implement is_wdba_realizable(),
needed by the above.
* tests/core/obligation.test: Test it.
* bin/man/spot-x.x, NEWS: Document it.
* bin/common_aoutput.cc, bin/common_aoutput.hh, bin/common_setup.cc:
Implement it.
* NEWS, bin/man/spot-x.x: Document it.
* tests/core/readsave.test: Test it.
