#199 UnBBayes-PR-OWL2 plugin requires direct import of PR-OWL2 schema

[Shou Matsumoto]

UnBBayes-PR-OWL2 plug-in (both the new and the old) seems to require that PR-OWL2 files (.owl files) declare direct import of PR-OWL 2 schema (https://www.pr-owl.org/pr-owl2.owl) or else it will save OWL properties to annotation properties and thus invalidate the ontology.

If this problem happens, then the user is forced to delete the auto-saved annotation properties in order to load the PR-OWL2 file again.