Static overlay: Modifying overlay on a running event

<image_inserter>
	<image>
		activate
		duration
		fade_in
		fade_out
		height
		image_x
		image_y
		layer
		opacity
		start_time
		width
		<image_inserter_input>
			certificate_file
			interface
			password
			uri
			username
		</image_inserter_input>
	</image>
</images_inserter>