Implemention of 2 EIDR properties #2469
Implemention of 2 EIDR properties #2469

This file got dropped accidentally during the fast-tracking of
COVID-changes last month. See github issue for history; originally
modeled with a single property but using two now to better capture
the semantics of EIDR.

schemaorg/schemaorg,schemaorg/schemaorg,vholland/schemaorg,vholland/schemaorg,schemaorg/schemaorg,vholland/schemaorg,vholland/schemaorg,schemaorg/schemaorg,schemaorg/schemaorg