adjust class-hierarchy task for failureresilience
adjust class-hierarchy task for failureresilience

For now we just want to read the class hierarchy for
ontologies, which use URI-style class-names in sentences.
This change will add the ability to walk through the ontologies
and continuining if one fails (it provides some error output).

ontohub/ontohub,ontohub/ontohub,ontohub/ontohub,ontohub/ontohub,ontohub/ontohub,ontohub/ontohub