COMMONS13 — Add additional metadata for external ontology registration

For visibility outside OMG I think we should be registering all our ontologies which I think may require a few extra items of metadata as here https://lov.linkeddata.es/Recommendations_Vocabulary_Design.pdf such as Dublin Core terms title and description (we have label and abstract), (date) issued and modified, and for elements, rdfs:comment (we have the more specific skos:definition). I think most of these could be added via automated script (e.g. Each skos:definition also becomes a rdfs:comment).