show oops button for owl2 ontologies only
refactored oops support check
Reject old versions of Hets
Error message in tests on old hets version.
A little styling.
Just renaming.
Add urn scheme to allowed uri schemes
Add skeleton for logic test
Merge remote-tracking branch 'origin/correcting175_restricting_oops_requests' into staging
Merge remote-tracking branch 'origin/correcting089_allowing_urn_scheme_in_iris' into staging

Conflicts:
	app/models/entity/readability.rb
	app/models/language.rb
Better config of allowed iri schemes, more useful test for logics.
Merged augmenting171... and heavily refactored especially the Hets module.

Conflicts:
	config/hets.yml
	lib/hets.rb