Feature end of level

At the completion of a level, there pops up a box that congratulates you for completing the level. This box presents to you the option to x out of the box so you can stare at your completed level and the option to go to the next level. When you finish the last level, the next level button will cause a UIAlertView to pop up and tell you you've finished all the levels. Upon dismissing that box, you go to the level selection view controller.

Things to add in the future:
- Fix the animation
- Change the dialog for when you finish the level. For example, it would say on the box itself you've completed all the levels and not give you an option to go to the nonexistent next level.
- Artwork