Update Growl to generate String constants.

This update is because NSPinnedString is being removed and because these constants leaked memory. Growl was using NSPinnedString which was doing a double retain and never deallocating the constants. Instead, these constants are now generated as String which will implicitly convert to an autoreleased NSString as needed.
Fix CTFontManagerError namespace
Merge branch 'hotfix/ctfontmanagererror-ns' of https://github.com/spicypixel/monobjc-tools into spicypixel-hotfix/ctfontmanagererror-ns