Fix seeds for URI in name ontology field.
Merge branch 'staging' of github.com:ontohub/ontohub into staging
Pulling from remote repositories is more efficient now.

solves #598
Refactored GitRepository::GetDiff

Lazy creation of diff to increase the performance.
solves #598 and #609
fix the extraction of internal iri when parsing

Since a hets update, hets does not enclose uris
consistently in angle brackets. We need to
check for them, before stripping the uri.

Also deactivates the Reference-Node-Callback (unnecessary).
Merge pull request #613 from ontohub/fix_iri_extraction

fix the extraction of internal iri when parsing
Merge branch 'staging' into staging.ontohub.org