Several changes to layer, camera and map dialogs: * Renamed CameraEditor and LayerEditor to CameraDialog and LayerDialog * Moved CameraDialog and LayerDialog into their own modules in scripts.gui so other components can use them. * Prettier camera dialog * Added LayerDialog to map wizard

<Panel title="Select an option">
	<VBox>
		<ScrollArea min_size="150,300">
			<ListBox name="optionDrop"/>	
		</ScrollArea>
		<HBox>
			<Button name="okButton" text="OK"/>
			<Button name="cancelButton" text="Cancel"/>
		</HBox>
	</VBox>
</Panel>