Add hungarian literal label
Add additional check when removing triple

The remove function of the jQuery rdf libraries does not check if the
triple that is to be remove from the triplestore exists in the triplestore.
If a triple is passed that is not in the triplestore, any triple will be
deleted.
Merge branch 'develop' into feature/rdfauthor-FormBuilder
Merge branch 'feature/rdfauthor-FormBuilder' into deployment/erm-hd