Validate student profile name field, use Backbone.js on the profile page

Changes:
* Validate student profile name field.
* Use Backbone for student profile JS.
* Use the same HTTP endpoint for both reading and updating profile info.

Reviewers: @AlasdairSwan @rlucioni 
FYI: @andy-armstrong 

[ECOM-409](https://openedx.atlassian.net/browse/ECOM-409)
I prefer not to call render from within an ```initialize``` method for a number of reasons:
1. If you use subclassing, then the superclass will render before the subclass has a chance to initialize
2. You can't call methods on your view before rendering it, because it will already be rendered
3. If you have views with subviews, you often don't want to render the subviews until everything has been created