x11/py-pyscreeze: New port: cross-platform screenshot module for python

PyScreeze can take screenshots, save them to files, and locate images within
the screen. This is useful if you have a small image of, say, a button that
needs to be clicked and want to locate it on the screen.

Screenshot functionality requires the Pillow module. OS X uses the
screencapture command, which comes with the operating system. Linux/FreeBSD
uses the scrot command.