* NEWS: Update.
* spot/twaalgos/cobuchi.hh: Declare to_dca() and nsa_to_nca().
* spot/twaalgos/cobuchi.cc: Implement them.
* python/spot/impl.i: Include new file for python bindings.
* spot/twaalgos/Makefile.am: Add new file.
* bin/autfilt.cc: Add --dca command line option. This option does not
return a deterministic automaton yet, but it will.
* tests/core/dca.test: Add tests for Büchi automata.
* tests/python/dca.py: Add a python script that builds a nondet. Streett
automaton.
* tests/python/dca.test: Add tests for Streett automata.
* tests/Makefile.am: Add all tests.
