Reviewer Andy : Move addressbook checkbox into Configure popup

- UI changes:
  - Remove checkbox from main page
  - Add checkbox to popup
  - Add nav bar to access the addressbook and dashboard more easily
- More generic method for getting and saving from multiple endpoints when opening/closing the configure popup, using $.with - will be useful when adding the ISC interface UI
- Refactor to reference the popup as the "configure modal", rather than the "simservs modal"
- Add GET handler for a single GAB listed called (used to only have PUT)

Tested live by playing with the UI, saving and refreshing various combinations of simservs XML and GAB