Hook up signing in to the worker and complete hooking up of the users presence list to the view

This set of changes do various things:

- Make the app.data.user model always present, so that it can be listened to from the views that require it (currently only LoginView).
- Hook up the signin function to go to the worker rather than being handled in services.js
- Hook up the update of the users list to the view
- Add a basic logout function to the worker for closing the web socket.
- Removes the old websocket code from services.js