Fix requiring libs (#1787) * Fix starting of hets with invoker. * Remove unneeded requires.

Namespace model `Symbol` in module `OntologyMember`.

Remove redundancy in a comment.

Run rename refactor script.

save entity/symbol only if it is not null.

fix entity annotation problem It seems due to old fixtures we did not realize that our annotation mechanic wasn't working properly anymore. However the problem is fixed (we can't rely on entity-uris in angle brackets anymore) and the spec has been updated for the hets-api.

adjust tarjan tree uses across project Use .for instead of .new.

ActiveRecord::RecordNotFound seems to be more appropriate, here.

catching more specific exception

using tarjan

replacing puts through logger

after an owl ontology is imported the entity tree is generated

parse labels as well as comments for entities.

utilize pre_axiom callback to parse descriptions.

determine whether a given axiom is an annotation.

add empty example callback for OWL.