Remove XML write option to control the relativization of URIs

[afs]

Change

The XML writers have a property setting to choose the way URIs are relativized.

These are no longer supported - the writers output relative URIs if the base if set, else full URIs.

Clear up the RDF/XML writers (basic and abbrev):

• issue warning if the app/user trys to set relativization policy
• remove tests (which used jena-iri) of inaccessible features

Are you interested in contributing a pull request for this task?

Yes

[afs]

Closed by #3529 (commit b72c874).