Websocket support

Websocket are designed for browser use but I see useful use cases in a java client as well:

• java clients for existing websites where changes are pushed to clients using websockets
• use of websockets to tunnel through firewalls
• put all communication behind single port on servlet engine.

A good example on emerging use is websocket+stomp (http://jmesnil.net/stomp-websocket/doc/, http://www.nighttale.net/activemq/activemq-54-stomp-over-web-sockets.html)

so I believe hc should support websocket clients.