hixie 76 is broken in node 6

[ArtemGovorov]

There's this breaking change in node 6, so it's required to pass the binary encoding as a second argument to all hash.update calls at:

• https://github.com/websockets/ws/blob/master/lib/WebSocketServer.js#L421,
• https://github.com/websockets/ws/blob/master/lib/WebSocketServer.js#L427,
• and also ideally at https://github.com/websockets/ws/blob/master/lib/WebSocketServer.js#L221

[lpinca]

Closing as Hixie-76 is no longer supported.