feature: print OWL entities by rdfs:label and print descriptions of OWL entities by rdfs:comment

[kodymoodley]

Some ontologies have identifier naming schemes for their entities (classes, properties) e.g. Food ontology, NCI thesaurus, SIO, etc. The human readable names and descriptions of these entities are sometimes expressed with rdfs:label and rdfs:comment. E.g. http://purl.obolibrary.org/obo/FOODON_0000100 rdfs:label "food product" and it has rdfs:comment "Food material for humans and animals which is processed with the intention that it be consumable as a whole or added to other food products." Introduce a method to be able to print these values for entities.