Ios8

This branch will prevent possible crashes and discontinue use of deprecated methods in iOS 8. Important changes of note are:
- UIAlertView is switched to UIAlertController if possible. Relevant for surveys.
- Use of interfaceOrientation in determining MPMiniNotification framing is unnecessary in iOS8 and is removed.
- Registration for push notifications in the example app has been updated to use newer methods. 
MixpanelDebug?