Added client options to specify server websocket listening port

Deploying my apps to OpenShift, I need the websocket client connecting to either 8000 (ws) or 8443 (wss), which was not retrieved correctly by the `window.location.host`.

I've added two options to the `clientOptions` object so that we may specify at which port the client may connect to the server through websockets.

This two options are `clientOptions.srvPort` for non https connections, and `clientOptions.srvSecurePort` for https connections.