Instantiate SessionManager in sip_audio_session.py

darcs-hash:20090324153424-58103-5b771a75953562a6f38869ed2c7db8809bf66893
Add streams attribute to SCSessionNewOutgoing notification

darcs-hash:20090324173027-58103-9b475f6d78eae937e5b2b4ef1dce900887f1ec14