AppState --> Snapshots Migration Sample

![savedgamescreenshot](https://cloud.githubusercontent.com/assets/8466666/4835575/0d55caf6-5fb9-11e4-8e0a-63c3677c2312.png)

Very basic sample app that demonstrates AppState and SavedGames while also showing how to migrate data.  @wolffg @claywilkinson @gguuss please review.

You can just return "Snapshot-" + appStateKey