VIVO-82 Remove unused actions in JenaAdminActions

No code in the application calls ctx.setAttribute("jenaPersistentOntModel").

The action "isIsomorphic" will do nothing if ctx.getAttribute("jenaPersistentOntModel") is null.
The action "removeUntypedResources" will throw an exception if ctx.getAttribute("jenaPersistentOntModel") is null.
Remove them.
Clean up JenaAdminActions to remove compiler warnings.

Remove commented code and unused methods. Add generics to Iterators or use for-each loops to avoid iterators entirely.
VIVO-92 Remove OntModelSelector.getTBoxModel(String ontologyURI)

This variant of getTBoxModel() is never called in the code, and it not implemented correctly in any of the implementations of OntModelSelector. Lose it.
Remove unused imports.