sip_send_file.py: do not wait for sound to finish if it's not enabled

darcs-hash:20081205084507-b2873-2ff8b5d29c348642597602210e6a6f23b1f9f107
added chatroom module: simplest msrp mixing

darcs-hash:20081205084537-b2873-98387cf856321e29ccc619b349441dfaf1c25dd7