Updated mediawiki/extensions
Project: mediawiki/extensions/Wikibase  e4f133b6ec29a2f365f8c3b18d80b06c91b013cf

Move RDF stuff into separate directory.

This gives classes for RDF handling a separate directory and moves
the external EasyRdf module into a central contribs directory.

Change-Id: I5947c4b4945c0fd22a2d0ca3881b272cefaa489b