api.securecall: if passed a string, lookup in _G for the method
widgets.frame: implement SetAttribute
widgets.frame: implement GetAttribute
api: implement getAvailableLocales
widgets.button: implement SetDisabledFontObject
widgets.button: implement SetText
widgets.frame: implement GetID
widgets.frame: implement SetID
tags.frame: read id attribute
widgets.button: implement UnlockHighlight
widgets.button: implement LockHighlight