zwaldowski/DZProgressController — pull request #4 by YuAo (2013-02-17 06:47:56+00:00)
Title: Fix a bug that causes the App's KeyWindow to become nil on iOS 5.

The application's key window ( `[UIApplication sharedApplication].keyWindow`) becomes nil on iOS 5 after a "show and hide" the DZProgressController.
This patch stores the App's original keyWindow on -[DZProgressController show] and set it back on -[DZProgressController hide].