Add Sparkle auto-update framework

[geerlingguy]

It would be nice for users to be able to be notified of updates to the app, so maybe incorporate Sparkle, and add the ability to let users update automatically.

http://sparkle.andymatuschak.org/

[geerlingguy]

Here's a nice little tutorial that was published pretty recently: http://www.cocoanetics.com/2012/11/in-house-mac-app-distribution-with-sparkle/