[WIP] fix pointer movement resolution, acceleration in hidpi

[mtwebster]

works except that when first logging in, the first time the mouse is moved, the pointer will jump to the lower-right corner of the screen.

keeping here so i don't forget about it :)

[leigh123linux]

Here's a 1 month has elapsed reminder.

[mtwebster]

der... need to wakeup.. fml

[clefebvre]

@mtwebster I'm going to close this one, purely for statistical reasons :)

We can always reopen it if it wakes up again.