Removes "LookupKeyboardDevice" and "LookupPointerDevice" in favor of
inputInfo.keyboard and inputInfo.pointer, respectively; all use cases
are non-XI compliant anyway.
Move the bell into an OS function, and use that if it's declared; else,
fall back to using the driver's function.
Remove the Linux keyboard bell function; just move it into the OS layer.
Use named initialisers when converting the old structures, and eliminate
unused functions.
Add KdOsAddInputDrivers, which adds all relevant input drivers.
Could possibly be refactored to KdAddInputDrivers, which called through
OsFuncs to a new function, if it existed.
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.
