Convert KDrive to GPE/GKE interface.
Add first-class drivers and enumerate every device separately through
Xi, instead of lamely attempting to aggregate them.
Add XKB support to the Linux keyboard driver.
Add 'thumb button' support to the tslib driver.
Rejig InitInput, so each DDX has to add a list of drivers it supports.
Support NewInputDeviceRequest, et al.
same width/height for front-buffer drawing. The fakexa code then uses
this extra space for offscreen pixmaps. Note that this tones down the
absurdity of fakexa's offscreen pixmap alignment requirements (odd
alignment is too weird, so stick with "24", which is still strange but
exists out there). It also fixes a couple of bugs in the fakexa
implementation revealed by using offscreen pixmaps.
