Support entity types

[nichtich]

GND has entity types such as work, person, organization... in field 075. This should be mapped to additional RDF statements with rdf:type to support selecting authority records by type of entity.

The GND entity types can be found in GND ontology, e.g. gndgen:

• b http://d-nb.info/standards/elementset/gnd#CorporateBody (=foaf:Organization)
• f http://d-nb.info/standards/elementset/gnd#ConferenceOrEvent
• g http://d-nb.info/standards/elementset/gnd#PlaceOrGeographicName
• p http://d-nb.info/standards/elementset/gnd#DifferentiatedPerson
• s http://d-nb.info/standards/elementset/gnd#SubjectHeading
• u http://d-nb.info/standards/elementset/gnd#Work

[danmichaelo]

Sweet, this is a very useful addition to MARC21 Authority!