THIS RETURNS THE GUI VALUE!!!
Returns the value of the specified field
Fields in format partname.fieldname
will return null when the part or field is null
Returns the class that corresponds to the name or null when not found See GuiDefaults.xml for more info on defining widgets
or call registerWidget(name, clazz) to register one yourself..
With implementing this interface, you state to xulux that you want the class
to be reused within the application, instead of creating a new instance all the name.