Add owl:rational and owl:real to match standard.

[sa-bpelakh]

Fixes #1378

Proposed Changes

• Add real and rational to the OWL namespace, as per standard

[nicholascar]

I've just added a note to indicate where these two elements are defined - in the OWL2 spec but not in the RDF file.

It's a pain that all elements of OWL, PROV etc aren't in the RDF docs...