LoadIdentityClut: Silence "unknown gpu" warning for Intel IGP's.

They work just fine with type-0 LUT at least on Linux, no need
to cry wolf.
PsychImaging: Add xorg.conf setup instructions for 16 bpc AMD framebuffer.

Also cleanup whitespace in the xorg.conf template files.
Update "help GStreamer" with setup instructions for GStreamer 1.x