move demo/msrpchat_send_message.py to share/sipclient/demos/msrpchat_send_message.py

darcs-hash:20090310100247-b2873-d4cb4e813a47e23d043370aa8933c4b4106031b4
rename msrpchat_send_message.py to msrp_send_message.py

darcs-hash:20090310100431-b2873-de25859f2c30f9d1a72449c08c6293013ad6321d