Batched transports

[darkl]

See advanced profile spec.

Being developed on "batched" branch.
TODO:

• Add suitable overloads for DefaultWampChannelFactory
• Add binary support
• Add a BatchedWebSocketTransport which wraps a given WebSocketTransport.

[BrannonKing]

+1 for this. I would love the ability to group messages and throttle the actual sending of the groups to four times per second, etc.