Remove methods that just call super class implementation

Hi! Thanks for creating a project for XCallbackURL. (I'm actually using XCallbackURL for a project I'm working on so this is awesome. :smiley_cat:)

This PR removes methods that just call the super classes method implementation, as well as ```shouldAutorotateToInterfaceOrientation:``` whose implementation is what the default behavior is already. I think it makes it easier to read the sample code and focus on the important bits.

Thanks again for the project! :octocat: