EventBusBridgeHook without affecting existing versions(backward compatible)

Looking at current SockJSServer there's no way to extend things easily with eventbus bridge. Thus I added additional methods without affecting current sockjs server and eventbusbridge class.
One can extend EventBusBridgeHook and create their own server hook in the application and setup SockJSServer with the hook.

    // ServerHook extends EventBusBridgeHook and implements the appropriate methods needed
    ServerHook hook = new ServerHook();

    SockJSServer sockJSServer = vertx.createSockJSServer(server);
    sockJSServer.setupHook(hook);