Add iOS 6.1 support.
Fix bug causing success and error images from not loading on iOS 7.

Silly me. I should have used instancesRespondToSelector: instead of
respondsToSelector: since the code is checking the class.
Fix positioning in iOS 8
- Transforms are no longer applied to windows for rotation, so ignore orientation specific logic
- Use window instead of screen for bounds
Merge pull request #272 from kirbyt/master

Added iOS 6.1 support.
Merge pull request #284 from dkasper/master

Fix positioning in iOS 8
Use new enum declaration.

The new(er) NS_ENUM declaration makes dealing with enumerated values in Swift really nice.
Fix for deprecated sizeWithFont: method in iOS 8 SDK
Properly handle orientation changes across iOS 7 and 8.
Merge pull request #336 from krzysztofzablocki/master

Properly handle orientation changes across iOS 7 and 8.
Merge pull request #335 from edwardmp/master

Fix for deprecated sizeWithFont: method in iOS 8 SDK
Merge pull request #332 from calebd/master

Use new enum declaration.
Fixed an issue when the top window is hidden because this is not the root window