Wordsmithing and punctuation fixes in chapter 1 and 2

Addy - I have done some additional reworking of wording in chapter 1 and done the same in chapter 2. Please review (make sure your meaning hasn't been lost!) and consider incorporating.

Regarding chapter 2 (Fundamentals), as a reader I found it somewhat redundant to what is covered in chapter 1, though it goes into far greater detail. By the end of it, I felt like I had had the MVC pattern explained to me a half-dozen times, but had yet to see an example of Backbone in action. I found the Cranium example a little confusing, in that I was expecting an example showing Backbone (since it is the subject of the book). At this point as a reader I am also more interested in examples of how I would use a framework to implement models, views, and controllers than in how such a framework could be implemented. 

I can understand the rational for introducing a hypothetical framework at this point, since Backbone does not have a Controller component. However, that could perhaps be worked around by explaining how event handlers within the view play the controller role. My recommendation would be to pull the Cranium section out and perhaps replace it with a simple example of end-user backbone code - this would also dovetail well with the reference to the Todo example at the end of the chapter and set up the deeper dive into Backbone's features in the next chapter.

Marc