Chapter 3: Backbone Basics - Updated to Backbone 1.0.0

Most of the updates are to the Collections section and a little in the RESTful Persistence section. Incorporates changes in pull request #374 as discussed therein. The updates to the Underscore function examples could definitely use some review!

Also fixes reference to this chapter in the introduction. Also, a fix to the Unit Testing chapter to refer to the upcoming chapters rather than "this" chapter.