Get RGB color of a specific screen location

[Beat Cornaz]

I have used the export snapshot and then the averaging. Works great. I had
forgotten about the export function (have been away from coding for 3
years).
I also had to implement Phil Davis' "set the screenMouseLoc to
globalLoc(tLocWithinMyStack)".
The average I got first (with only the mouseLoc) was offsetted to where I
clicked. Now it purs :-)

Thanks again, Beat