V2.0 stats updates

Make sure you use the Debug or Release configs when you try it out, as they point to the production server.

Changes:
- add Configuration class (and plist) for having dev/production specific variables
- add Development build config (duplicate of Debug) that uses values from Development confiuration (Debug and Release both use production config)
- add Stats api v2
  - add stats client api key for PhishOD 
  - add registration via api in settings tab
  - add controller for sign in instead of UIAlertView in settings tab
  - send plays anonymously when no user logged in
  - allow global stats to be viewed when no user logged in
  - add a variety of global stats
  - add user's top tracks
  - add "more stats" view to show more stats while avoiding clutter
- add favoriting for tracks, shows, tours & venues
- add global activity view

Let me know if you have any suggestions or anything!