Backbone version of the course outline page

STUD-1726

Converted the course outline page to Backbone so as to support dynamic client-side updating.
The comment on the outer function attempted to explain this, but I've added a doc string here too. The idea is that when you deep link to a section or a subsection, we want to show it fully expanded so that you don't have to immediately start expanding just to see what's there. The way the client handles this is through the initialState option, one of the settings of which is a list of locators that should be initially expanded.