Functions for display of graphics-format images in a no-frills 
 viewing window (an ImageWindow).
 Supported image formats include GIF, JPEG, PNG and FITS,
 which may be compressed.
displayBasicImage( label, loc )
label may be any string which identifies the window
 for display, so that multiple images may be displayed in different
 windows without getting in each others' way.
 loc should be a filename or URL, pointing to an image in
 a format that this viewer understands.
label (String): identifies the window in which the image will be displayedloc (String): image location