Connects to a stomp server, subscribes to topics on demand, relays messages to the StompProxyServerFactory
Accepts WebSocket requests from clients.
Makes subscription requests to the StompConsumer based on the client's http_request_path attributes.
Mantains a list of all clients -- should also maintain what they subscribed to. (Once all clients to a topic have disconnected, we can request the StompConsumer to unsubscribe itself.)
Need to maintain two pieces of data for each client: 1. Requested destination 2. Filter parameters, if any