Revert "Revert "Fix xf86DeleteDriver and various places that use it""

This reverts commit 917410b7d22014c6866b7748a8154d3d83a569da.
Fix infinite-loop when deleting drivers on hybrid systems.

Really need to go back and work out exactly what the xf86DriversList should be, and then fix all the bits where that doesn't work
Update to new surface creation API

We now put each surface on the output it's meant to be on!
Add API to get the offset into the X window
Try waiting for xmir_surface_release
Create a properly-sized screen pixmap on resize
Allow xf86_cursors_init to succeed without HW cursor support

The xf86Cursor code does all sorts of other things on top of HW cursor support,
such as not die screaming in a horrible fire should someone have the temerity
to try and change the display size
xmir: reload cursors after display resize