Prepare app for push notifications
Register for remote notifications on startup
Enable button for pushers
Create PushViewController
Add confirmation alert
Connect to Parse Push
Reduce calls to enableButtonForPushers()
Fix nil reference crash

Occurred when causing viewWillDisappear to be followed by viewDidAppear
instead of viewDidDisappear with the swipe-from-left gesture.
Fix launch screen title text
Fix rare nil reference crash
Improve Push view logic