Upgraded Firebase dependency to 1.1.x and other example dependencies

@davideast - Please review and merge. I want to get all of our bindings upgraded to our latest libraries in time for the new queries stuff to drop so that transitioning is as easy as possible. I also am working to get all of our `firebase bootstrap` examples to work and be easy to understand. As a result, I made two main changes here:
1. Upgraded the Firebase dependency to 1.1.x. We will bump this to 2.0.x soon.
2. Upgraded the dependencies of all libraries in the Todo app example and did some cleanup there. We now pull BackFire from the Firebase CDN instead of including it locally. We also use more recent versions of Underscore, Backbone, and jQuery. I also cleaned up the code a bit and added some comments.