added sample code for programmably saving a screen-shot image
added sample code for programmably saving a screen-shot image

walterbender/turtleflags,walterbender/AmazonasTortuga,walterbender/turtleconfusion,max630/turtleart-hacks,AlanJAS/turtleart,walterbender/turtleartmini,walterbender/turtle3D,walterbender/turtleart,max630/turtleart-hacks