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

last error at generating the links

fix logic==nil problematic for parsing callbacks.

add logic specific parsing callback It seems appropiate (since we will we have a lot of logic specific parsing decisions to make) to extract this into its own callback module. This should prevent unnecessary cluttering of app/models/ontology/import.rb and the OntologyParser itself.