UI updated for iOS7 + enhancements and bug fixes

I removed the need for background images for the buttons. KOKeyboardRow is now subclass of UIInputView and is integrated in the iOS7 keyboard (inheriting its background). I also fixed a bug with the accuracy of the text selection functionality when using the track point button. I also made it so when the user finishes making a selection, the cut/copy/paste menu automatically displays. Lastly, the keys now make the same click sound as any other key.