Merge pull request #1 from justinsb/clean_cleanup

Close down channels that we open in RpcServer
Merge pull request #3 from justinsb/set_callback

Set the callback when notifyOnCancel is called
Merge pull request #2 from justinsb/expose_caller_address

Expose the remote address via an interface which the Controller implements
Add some TODO notes
Set the callback when notifyOnCancel is called