add docstring for GreenSession.terminate and make it accept *args and **kwargs

darcs-hash:20090323081934-b2873-441003511d4762934ea47da4ce1a712635b6b1d0
make GreenSession account for MSRPChatDidFail and add some docstrings here

darcs-hash:20090323082023-b2873-7e1d42b733fb0e1a4c58810faea413ab4d469d53