* Ability to crawl xhv:meta and maybe rdfs:seeAlso, powder-s:describedby, etc links.
	- This might be better as a separate module?
	- Overlaps with HTTP-LRDD?

* Investigate why the following two root elements produced different triples:
	<html property="ex:foo" content="foo" />
	<html property="ex:foo" content="foo" about="" />
	See note 'x876587' in source code. Need to check rdfa-syntax algorithm to see if intended!

* Track changes to RDFa 1.1
