[Xorg] XINPUT additions; maybe add an XDEVICE extension?

[Joe Krahn]

A lot of XINPUT commands are written as if they were made as
interfaces to X extensions in general. For example, XINPUT
defines XSelectExtensionEvent(), which is (I think) the only
standard interface to non-hardwired extension event types.
Also, many input devices are really output devices as well,
even in XINPUT which defines output as Feedback events.

IMHO, XINPUT should really be XDEVICE. But, XINPUT is
already well established. So, perhaps a development plan
could be to add a new extension called XDEVICE that
does all of the device managament and configuration, and
could be designed not just for input devices, but for any
device.

Regardless, XINPUT itself still needs some updating.

Joe