* Split EventListener into several internal subclasses. This fixes issue with multiple inheritance where each BaseClass.__init__() call would overwrite the previous one. This meant that you could only add EventListener to one type of event managers. * MapView now adds maps and layers to EventListener * LayerEditor should now fetch only NameClash exceptions when creating or editing layers

<HBox opaque='1'>
	<Button name="quitButton" text="Quit"/>
</HBox>