RDF / Fix parser errors

[fxp]

Fix the following error messages from RDF service:

• Error: {W116} RFC 3066 section 2.3 mandates the use of 'en' instead of 'eng'.[Line = 11, Column = 33]
• Error: {W116} RFC 3066 section 2.3 mandates the use of 'en' instead of 'eng'.[Line = 13, Column = 33]

Warning Messages:

• Warning: {W113} rdf:label is not a recognized RDF property or type.[Line = 13, Column = 33] Use rdfs:label
• Don’t use dc: - use dct: dc: is obsolete.
• dcat:Distribution is wrongly used.

[fxp]

master commit 397aed16046841bf755586009a0c5d7e4bac2f4e