Made sip_audio_session close log file after at exit

darcs-hash:20081128161531-1e3d8-e18af2053e8bdf536d71b2908bd85260b3d4f4cc
Made sip_audio_session print sip trace log filename

darcs-hash:20081128161626-1e3d8-de1afc6cc6f4436b115b996b2ae0b6ecd8c86a98