Switched to websocket/driver and improved websocket handling

This pull request should be considered a WIP, I just wanted to open it for some feedback and sharing.

In general I found WebSocket support in Reel to be a tad flaky and hard to get working since there are not many good examples of keeping a long running persistent WebSocket open in Reel.

This pull request does the following:

* Complete re-write of the websocket handler
* Uses websocket/driver instead of websocket_parser
* Detaches the connection instead of just hijacking the socket
* Easy support for long running persistent connection
 
What I would still like to achieve with websocket support in reel:

* Automatic pinging of client from server if connection is idle for 30s or more
* A way to signal and interrupt the websocket outside of client disconnect/closing
* Specs ( I'm horrible at writing specs )
* Examples ( Lots of examples on how to use this properly and easily! )
maybe async.handle_websocket_request(request, connection) migth work? @tarcieri