Start restructuring the methods which communicate with the database to be a little more flexible and DRY.
Merge branch 'master' into screenly-ui
Improve documentation and code style
Use the new get_assets_grouped() method to get a list of the active and inactive assets for use in rendering the index template.
Add Underscore and Backbone, which we'll need for the interactive index page.
Start Javascript for interactive index page.
Add simple API for obtaining a list of Assets.
Create Backbone collections for Assets, ActiveAssets, and InactiveAssets.

These are populated automatically via AJAX on page load.
Remove unneeded variable.