Fix for behavioral bugs after changing a view controller.
Block indirection fixed
Simplified UIViewController category

Objective-C runtime can handle the message to nil. Now it has only one return.
Merge pull request #178 from alistra/patch-1

Block indirection fixed
Merge pull request #179 from alistra/patch-2

Simplified UIViewController category
Merge pull request #177 from XeresRazor/master

Fix for behavioral bugs after changing a view controller.