Add federated repository fetching methods to repository manager
Add PoddArtifactManager.getSchemaImports to enable selection of the
permanent repository location based on which schemas are being imported
by the given artifact
Implement new methods in PoddRepositoryManagerImpl
implement and use new methods in PoddArtifactManagerImpl
Use new methods in upload artifact resource impl

Add fixme note about pushing the relevant function into
PoddArtifactManager
Use new method in AddObjectResourceImpl
Migrate PoddSchemaManagerImpl to use new repository manager methods
Migrate methods in PoddFileRepositoryManagerImpl
migrate PoddRepositoryManagerTest
Migrate PoddFileRepositoryManagerImplTest
Migrate AbstractPoddFileRepositoryManagerTest to new repository methods
Migrate PoddArtifactManager test to new methods, roughly...
remove runtime exception to see how many tests still work
recognise ontologies without versions attached as versionless
check the number of ontology IDs that were parsed in and throw
exceptions and log warnings early for unusual situations
make versionless ontology retrieval optional

the previous change made unit tests for OntologyUtils fail, as we assume
that we are able to send in any number of rdf:type owl:Ontology
statements and the system will not recognise them unless they have an
owl:versionIRI statement attached to them
Ignore test that was not theoretically supported previously

All ontologies should have had version IRIs to work in the previous
method
Close connection after each call in getTopObjectLabels