Is it possible to just pass a style theme in the slave tag as an attribute the way that includes do?
<slave theme=@theme@>
so that file references might be:
<img src="@theme@/filename"
Also, could <box> be called something else, such as <encase> or <wrap>?
There are many places where I can see using an include tag to wrap around another include. A generalized version of <box> could be really useful.
I'd see it work sort of like this:
<wrap src="filepath"><include src="filepath2"></wrap>
That way there would be less need to pass properties through multiple layers of include tags with special handling for special cases.