Part of #113.

* src/twaalgos/emptiness.cc, src/twaalgos/emptiness.hh (tgba_run):
Rename as ...
(twa_run): ... this.
* NEWS: Mention it.
* iface/ltsmin/modelcheck.cc, src/tests/complementation.cc,
src/tests/emptchk.cc, src/tests/ikwiad.cc, src/tests/randtgba.cc,
src/twa/twa.hh, src/twaalgos/bfssteps.cc, src/twaalgos/bfssteps.hh,
src/twaalgos/gtec/ce.cc, src/twaalgos/gtec/ce.hh,
src/twaalgos/gv04.cc, src/twaalgos/magic.cc, src/twaalgos/minimize.cc,
src/twaalgos/ndfs_result.hxx, src/twaalgos/projrun.cc,
src/twaalgos/projrun.hh, src/twaalgos/reducerun.cc,
src/twaalgos/reducerun.hh, src/twaalgos/replayrun.cc,
src/twaalgos/replayrun.hh, src/twaalgos/se05.cc, src/twaalgos/word.cc,
src/twaalgos/word.hh, wrap/python/ajax/spotcgi.in,
wrap/python/spot_impl.i: Adjust.