Move JS to the footer

Get down there where you belong!
Changes to JS load order

Plus pull in a CDN version of Backbone!
Asset Pipeline and Autocomplete refactor

So I wanted to rip out jQuery UI because it's big and only used for the
autocomplete box. So then I ripped out the autocomplete box and built a
new one with Backbone. But then everything is bad because it's in
public/ and doesn't use the assets pipeline. So then I moved everything
around and probably broke things in a bad way.

Anyway, here it is.
Clean up application styles
Refactor the JS stuff

Ideally I want the player-select dropdown to be not tied to the context
in which it is displayed (similiar to the old API). So it should trigger
an `autocomplete:selected` event when the admin picks a player and then
the enclosing view knows what to do with it.