Fast replacement for getframe that works in background

New getframebg -uses hardcopy. Only supports grabbing entire figure window. Has issues depending on renderer.

Signed-off-by: horchler <adh9@case.edu>
Minor update -polished code a bit, reordered properties, added getframebg to ZIP

Fixed MLint warnings in code. Reordered some properties when printed by user. Updated creation string in atoms. All unit tests pass with new versions of Matlab, Java, OS X, and QuickTime.

Edited Readme.

Signed-off-by: horchler <adh9@case.edu>