Websocket implementation

[tshemsedinov]

Module ws is good enough but websocket is a simple spec so we don't need everything from this ws and can implement own simple implementation (just for backend, all browsers have native support).

[georgolden]

I want to implement uWebsocket support (maybe in a month) for metacom as well. They are secure and fast as hell. Why not to have multiple realisations? https://github.com/uNetworking/uWebSockets.js/