Status items are the things on the right end of the Mac menu bar, like the
clock and volume widget.  It turns out that they are displayed at a higher
window level than everything else in the menu bar.  For the case where the
displays are not captured for a full-screen window, the window ends up at the
same window level as the status items, and they would sometimes end up on top.
They would draw over the full-screen window and could be clicked.

This was probably taken from the YUV shaders, incorrectly and in reverse
logic. It did happen to work though because fragment.texcoord[0].w is 1.0.

On high-resolution Retina displays, the OS X window backing store has twice the
pixels as Wine's window backing store.  So, our images get scaled up.  Core
Graphics had been interpolating/smoothing the image, which resulted in
fuzziness.  This tells it not to do that.

I had assumed this wouldn't be necessary since we pass FALSE for the
shouldInterpolate parameter of CGImageCreate() when we create the images.
Apparently, that's not sufficient.