Remove double state warning for Invitation EARLY state in sip_audio_session.py

darcs-hash:20090126135018-58103-811a8dc3a550f79861fdea9e6469a679c874c12a
Stop ringing once media is negotiated in sip_audio_session.py

darcs-hash:20090126135049-58103-4ad2690caeb722149e4583aad3f7012fbbd7aa0a