Websocket API #3

By outside demand: To enable clients to connect from other languages in a halfway standard way, the option of enabling Websocket connections would be nice.

Apparently, not much extra code is needed to enable Websocket connections, since they're basically upgraded HTTP connections, so after an initial handshake the internal code might stay the same (ref: https://en.wikipedia.org/wiki/WebSocket#WebSocket_protocol_handshake). Even so, it might be a good idea to separate the Websocket code from the regular socket code. Further examples: https://gist.github.com/jkp/3136208 and http://autobahn.ws/python/