function being called can sometimes take a long time to return and we
almost always want a new thread to be created if there are no free
threads available.

by setting the length correctly and by doing a case-insentive compare
on the GUID string that is returned.

should set the it to have the maximum possible length and size rather
than a modulus of the actual length.

Fix test failures for RtlInitUnicodeString on Windows XP upwards.

ole32: Make sure to reset the message state if it has been changed in RPC_ExecuteCall before returning.

Fix the hrFault parameter passed into the ClientNotify function in 
ClientRpcChannelBuffer_SendReceive so that it is correct in the case of 
messages dispatched with PostMessage.
Only unmarshal ORPCTHAT for non-fault packets.