* [RDF_MAN_DUPLICATES,NEW] Added rdf_duplicates/2 which returns the number of duplicate triple tokens in a given graph.
* [RDF_NTRIPLES_WRITE,FIX] Restraction of bnode admin was incorrect.
* [RDF_NTRIPLES_WRITE,FIX] IRI replacements for bnodes were not written according to IRI syntax.