Updated for iOS 8, removed redundant property

Instead of using disableUserInteractionOfSuperview one should use
userInteractionEnabled on the HTProgressHUD instance to let touches
through to the superview.
Added support for base SDK < 8.0 while retaining 8.0 features
Merge branch 'JonasGessner-master'
Add showAboveView methods
Remove copyright comments
Change method bracket coding conventions