Updates for Xcode 6.1 - Removing Compiler Warnings

Hi! I'm Fernando, this is my first pull request, so my apologies if I had changed something in the wrong way, My initial idea with these changes was to remove some warnings I had in my xCode (6.1), compiling for iOS 8.1

Thank you so much for publish this control, it helped me a lot.


Fernando Sosa.
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Changes Description

Xcode 6.1 Compiler options added in order to help developers to find
and fix possible warnings.

Explicit cast to unsigned int were added in order to remove compiler
warnings.

options:UIViewAnimationCurveEaseOut
was replaced by
options:UIViewAnimationOptionCurveEaseIn

UITextAlignmentCenter
was replaced by
NSTextAlignmentCenter