sip_session: set chat.message_received_sound and chat_message_sent_sound in the script

darcs-hash:20090327102021-b2873-f0f7df87680f8741bf4541471548b15d03b19e3f
sip_session: print RTP info and User-Agent like sip_audio_session does

darcs-hash:20090327105231-b2873-a490e5a7790f46b606c0a204c9c1962b262d021c