Removed Parse JavaScript SDK in favor of vanilla Backbone + internal API.

I don't like how Parse forked Backbone. Their fork is based on an older version of Backbone that's missing some of the latest conveniences, plus there's potential issues with extending Parse/Backbone classes down the road (i.e. implementing nested models, etc.). So I ripped out the Parse JS SDK and I'm using vanilla Backbone instead.

Because of this, I introduced an internal API that my Backbone app can talk to.

Also, I enabled anti-CSRF tokens for all Backbone XHR requests (although I've been unable to verify that it's working properly yet).

Lastly, I've introduced an EventAggregator on the client-side to decouple views and collections.