ZVISION: Remove CLIPs from mutateImage

Due to the math of the Panorama/Tilt, all pixel offsets are going to be closer
to the center of the image. Also, mutateImage is now being called on a
finished buffer, rather than an image at a time. Therefore, it no longer has to
handle image wrapping. Thus, there is no case in which a pixel offset would
be outside the image bounds.