* DONE document protocol
* DONE Ascending everywhere
* DONE document KRPC module
* DONE move exsamples to tests
* DONE make HUnit tests
* DONE run server in test automatically
* DONE use one socket everywhere
* DONE fix performance issues
* DONE add readme
* DONE return scheme back
* DONE add Show instance for Method
* TODO add BEncodable instance for Method
* TODO hide async api
* TODO expose client addr in server-side
* TODO major version bump (reason: exported type changed)