This patch tracks the protocol changes which introduce more complex
semantics for RandR output properties including pending and valid value
information.
Add function to keep pointer within valid crtc areas.
Finish event delivery and swapping code.
Separate configuration from layout changes to send correct events.
Provide a Xinerama implementation when DIX version isn't enabled. This
version exposes each crtc as a separate 'screen' and reports the size of
that patch. The extension also sends ConfigureNotify events to the root
window whenever crtcs change so that applications will re-fetch xinerama
information. This actually works for metacity.