Subprotocol ID name and version

In 5/5/2015 TC meeting, John Fallows suggested that a proper subprotocol ID would be lower case and optionally include the subprotocol (AMQP) version number, e.g. amqp/1.0. There was also a discussion of where to negotiate the version - at the websockets exchange or at AMQP level. Both of these questions should be resolved and any spec changes made as needed.