move Ont Class, etc to their own file

[tgbugs]

Something like builder or similar, but need to come up with a better name. These depend on git and thus fall outside the core. Alternately, come up with a better version of makeGraph that covers the 80% use case and doesn't have all the baggage.

[tgbugs]

OntGraph is the future, but the last 20% needed to replace Ont and other ontology generation code is going to be a nightmare to refactor.