Merge: Websockets

Fixed websockets with the new and improved sockets.

While I'm at it, changed a bit the way it works, the old one was a bit (a lot ?) quick and dirty, so here's that.

Pull-Request: #1096
Reviewed-by: Jean Privat <jean@pryen.org>
Reviewed-by: Alexandre Terrasa <alexandre@moz-code.org>

diff --cc lib/socket/socket.nit
Simple merge

diff --cc lib/standard/string.nit
Simple merge