[broadway] Stream data over websocket

[broadway] Stream data over websocket

The zlib compressed xmlhttprequest thing was a nice hack, but it doesn't
really work in production. Its not portable, doesn't have enought API
(missing notification for closed sockets) and having to synchronize
between two different connections in a reliable way is a pain.

So, we're going everything over the websocket. This is a pure switch,
but after this we want to modify the protocol to work better over
the uncompressed utf8 transport of websockets.