xinput: Add XI v2.0

xinput: Add XI v2.0

Introduced with v2.0 have been various new types, structures, 21
requests and 12 XGE events.

All new requests have the "XI" prefix in the name. This prefix can be
found in the spec too and avoids name clashes with requests found in
prior versions of XI (at least that's (Un)GrabDevice).

All new events are X Generic Events. They've a different header then
"normal" events. Therefor we've to mark them with the attribute 'xge'
set to 'true'.

To prevent another name clash one new structure had to be prefixed,
too: XIDeviceInfo.

Signed-off-by: Daniel Martin <consume.noise@gmail.com>