Playlists Divided in Sections

![screen shot 2014-12-02 at 1 06 49 am](https://cloud.githubusercontent.com/assets/4207886/5251946/a0fe0e88-79bf-11e4-9817-644e71d07eec.png)

I believe it would require lot of changes as I am not good at Backbone.
@rtibbles would you have recommendations how to make this more idiomatic to our code?