For your convenience pools now have a function called purgeLoadedResources exposed to python which will delete all loaded resources that have a ref count of zero. You can use this after closing a map or something alike. It may however impact performance, as the next map may very well reload the same resources. Just be aware of that. :-)

<Window title="Elevation Editor">
	<HBox>
		<VBox name="Metadata Properties">
		</VBox>
		<VBox>
			<Button name="layerButton" text="Edit Layer"/>
			<Spacer /> 		
			<Button name="closeButton" text="Close"/>
		</VBox>
	</HBox>
</Window>