Fix GH-6 migrate to rdf4j

[abrokenjester]

This PR addresses issue #6

Changes:

• migrate from sesame 2.7 to rdf4j 2.4
• migrate from owl api 4.2 to 5.1

The owl api version bump was necessary because the older version used sesame internally.

This PR is not ready for merge as-is: in particular the class AnonymousResourceHandler needs scrutiny. This class used a lot of OWL API functionality that has significantly changed between version 4 and 5, and I couldn't immediately make sense of it. Feedback most welcome. My fork should be editable to the maintainers so if you wish to push fixes to my repo/branch, by all means do.

[matthewhorridge]

Hi @jeenbroekstra thanks a lot for the contribution! Much appreciated.

We are kind of nervous about updating Protege to OWL API 5 right now as it is backwards incompatible with 4 and thus updating Protege with 5 has the potential to break a lot of plugins. I think we'll look at doing this for Protege 6 (we have a big Protege 5.5 release coming soon).

[abrokenjester]

That makes sense. Unfortunately we can't switch to rdf4j without this upgrade. Only option I see is that we convince the owl API project to release a 4.3 release that updates to java 8 and rdf4j but doesn't change its own APIs. Not sure if that's realistic though.

[abrokenjester]

@matthewhorridge you want to keep this PR open for future reference, or do you prefer to close it for now? Either way once you've started migration to OWLAPI 5 feel free to give me a nudge, happy to assist with sesame to rdf4j migration any way I can.

[matthewhorridge]

@jeenbroekstra yes, I'll keep it open for future reference. Thanks so much for the kind offer of assistance - I really appreciate it!