MsgRefactor: Add Direction.In/Out and logic in messages to do the right
thing for handling buffers and conversions. ConvertOut can be called
multiple times.
Add detail message logging into SyncMsg. Each message can do individual logging.
MsgRefactor: Add regionContext parameter to every SyncMsg creation
so msgs will have a reference back to their context even when the message
is being processed deep inside a SyncConnector.