Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Update DRM to CVS snapshot as of 2005-11-28. Notable changes:
- S3 Savage driver ported.
- Added support for ATI_fragment_shader registers for r200.
- Improved r300 support, needed for latest r300 DRI driver.
- (possibly) r300 PCIE support, needs X.Org server from CVS.
- Added support for PCI Matrox cards.
- Software fallbacks fixed for Rage 128, which used to render badly or hang.
- Some issues reported by WITNESS are fixed.
- i915 module Makefile added, as the driver may now be working, but is untested.
- Added scripts for copying and preprocessing DRM CVS for inclusion in the
kernel. Thanks to Daniel Stone for getting me started on that.