Merge pull request #1 from acka47/master

Add lv:urn & type DatatypeProperties as such.
Changed domain of lv:isil from foaf:Organization to foaf:Agent

There are entities related to an ISIL which are not organizations
Merge pull request #3 from Zeitschriftendatenbank/master

Changed domain of lv:isil from foaf:Organization to foaf:Agent