Refactor data handling, decodePacket/handlePacket
Update node-minecraft-protocol - add writeRaw() for proxy, since client encodes its own packets

deathcap/node-minecraft-protocol@b752247008c9aed38e135eb682ee0212f3f24e70 Add writeRaw(), allows client to encode data itself (useful for proxies)
Use binary protocol for WS client-> WSMC proxy communication, too. Closes GH-1

The WebSocket client (example mcwebchat) now encodes packets, and sends to
the proxy for it to simply forward to the MC server as-is, without decoding.
Previous commits did the same but in the opposite direction, forwarding MC
packets from the MC server to the WS client, having the client decode them.
With these changes, WSMC is now fully using binary WebSockets.