dinput: Add mouse warp override config option (resend)

[Vitaliy Margolen]

Stefan Dösinger wrote:
> Just for the record, I think we really want this patch. XInput 2 is
> currently under development, so we cannot fix the issue properly right
> now. Even if we have XI2, there will still be old X servers around for
> ages.
> 

That's assuming XI2 will be able to send actual mouse (other devices)
movements to requesting applications. Right now nothing can (DGA doesn't
count it's not available anymore).

Vitaliy.