sip_session: make prompt reflect the streams used

darcs-hash:20090324103524-b2873-5740fcbdc894b48bbb5bf4cd0c3efc3390024e97
sip_session: proper handling of bonjour account

darcs-hash:20090324112603-b2873-d5f0ecce6a3f4f99a75111a27d0d4484f9a05873