Progress: styling done, update on model change done

- Styling pretty much done
- Also added code to update the reading budget if the model changes.
  This was actually pretty hard to pull off. The current method makes
  use of custom events. Check out the ReadingBudget view and the
  goals-view (where the button click is delegated), and also the
  popup-goals-controller.
Merge branch 'issue_9' of github.com:Slimformation/slimformation into issue_9