cleanup
perform file reference validation after inferencing so that sparql
queries can operate on the inferred graph to identify what the parent
object is
Add ability to discover file references via parent, and discover parents
via file reference
Fix File Reference manager test so that it can handle the new ability to
get Parent IRI
Fix EditArtifactResourceImplTest.testEditArtifactBasicRdf

The reasoner seems to be generating inferred triples that have
XSD:string attached for any triples that are RDF-1.0 Plain Literals

In RDF-1.1 this situation will not occur as all plain literal will be
typed as XSD:string.
Fix SSHFileReferenceProcessorFactoryImplTest

The addition of the parent URI added an additional unique subject URI,
which was causing the tests to fail