proper loading of page

in this pull request, it now waits for the facebook api call to return 'connected' or 'not connected', and loads the proper page depending on that. we might possibly want a 'loading' screen or text. to test:
1. Be logged into Facebook, reload the page. Unless Facebook is being slow, it should take you to the map page without hitting the login page. If Facebook is being slow, it'll load the login page in 2.5 seconds.
2. Be logged out of Facebook in the app, reload the page. It should take you to the login page.
3. Be logged out of Facebook completely (in your browser, just go incognito). It should take you to the login page.