Tidied some random unused variables in VS2010 build files
Extra trace log for sound channel errors.
Tidy up of strange log messages when deleting an OPAL transport, to do with closing already closed channels. Benign but confusing.
Fixed "by inspection" memory leak, pretty sure this never actually happens.
Fixed compile of OpenPhone when presence disabled.
Fixed SDP connect address when NAT is used on incoming call.
Fixed SDP addresses for RTP session when NAT *not* used, broken in previous fix.