rdf 6.x-1.0-alpha6

This is hopefully the last alpha release before the project moves to beta stage. Please report any and all problems you may experience.

Upgrade notes: be sure to disable and uninstall the RDF Schema module once you've upgraded to this release. All RDF Schema functionality has been folded into the base RDF module, and the RDF Schema placeholder will be removed in the next release.

Changes since 6.x-1.0-alpha5: full details at http://drupal.org/project/cvs/182305.

Note: This is experimental software meant for advanced users; assume nothing works, and you may be pleasantly surprised. And when it breaks, you get to keep both pieces.