Add function to keep pointer within valid crtc areas.
Finish event delivery and swapping code.
Separate configuration from layout changes to send correct events.
Output options and mode origins both affected driver ABI. memmove mistakes
were causing 'Freeing resource which isn't there' messages.
Prune unused non-user defined modes from available list now.
RandR is getting too big to live in one file; split into one file per object
type (crtc, mode, screen), leaving the rest of the code in randr.c.
Code is slowly approaching the point where it will drop-in as a replacement
for the old 1.0 implementation.
