Improved logic for determining source IP address used in signalling

Ignore-this: b149b69fe6c74cd97eeccc9c73a10560

darcs-hash:20100818115107-1e3d8-364a8fdd476553a0ed7885edcbeeff83e7328c7d
Removed IP address from rtcp SDP attribute

Ignore-this: 1cb361b7252225ed96a59da97d088695

darcs-hash:20100818121155-1e3d8-6485aacb8fc0d25ab79eb2a6e741c5e4daea22d6