Fix hover area for divs with css transforms
The problem is that a rotated div doesn't trigger the :hover state (or
location of the mouse.
Non transformed layers are now being hit last, not through or in-between
The paint order says that the divs creating stacking contexts (including
transforms) are painted after the other siblings so they should be hit
tested in the reverse order. Also, a rotated div in a non-rotated parent
should be hit in its entire area, not hit its parent's background, even
if the z-coordinate is negative where the mouse is located.