Fixed bug with setting font-name without setting font-size

This was proposed by @basitali in https://github.com/tombenner/nui/pull/70
Removed unused fontSizeProperty variable in NUILabelRenderer
Add support for styling UIControl
Removed the UIControl from the Storyboard for aesthetic consistency
Removed Control from the default NSS
Added Control's supported properties to the README
Merge branch 'master' of git://github.com/tombenner/nui