Show genre track count and improve efficiency of 
genreSelect directive
Get filtering working on customize page
Abstract filter logic and get create menu working
Extract track info into its own directive
Fix '$digest already in progress' error where 
programmatically updating the genre-select input
forced a digest() when one already occurs when the page 
loads.
Fix issue where tracks aren't filtered on page load
Add image to show how to make a Pandora account
public.
Add 'track by' to ng-repeat to increase efficiency
of DOM manipulation
Update signature of PandoraData service
Working nav menu
Fix 'track by' bug where identical IDs were generated
on page refreshes
Minor naming updates to SpotifyTrackPresenter
Add track preview support
When no tracks are filtered, make the create menu
unselectable
Filter tracks by market