i915 vblanks can be generated from either pipe a or b, however a disabled
pipe generates no interrupts. This change allows the X server to select
which pipe generates vblank interrupts.

From: Keith Packard <keith.packard@intel.com> via DRM CVS
Signed-off-by: NDave Airlie <airlied@linux.ie>

Fix CMDBUFFER path, add heap destroy and flesh out sarea for rotation
(Tungsten Graphics)

From: Alan Hourihane <alanh@tungstengraphics.com>
Signed-off-by: NDave Airlie <airlied@linux.ie>

Add support for vblank ioctls to i915 driver

From: Dave Airlie <airlied@linux.ie>
Signed-off-by: NDave Airlie <airlied@linux.ie>

From: Alan Hourihane
Signed-off-by: NDavid Airlie <airlied@linux.ie>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!