
"iffsunshow" pops up a suntools window of exactly the size of the image,
and then halftones the image into it.  All the resizing features work right.
Sorry, no automatic rescaling.

Since you out there won't have an "iff" library, you'll have to write a
routine to read an image header returning various items such as image size,
and a routine to get a row of the image.  The halftone code will work with
images with various bits-per-pixel, from 1 to (maybe) 24, if your input
routines support it.

This was originally written for suntools on a sun-2 under release 2.1 or 2.2.
We just tried it on a sun-3 under release 3.2 and it works there too.

Compile it with -lsuntool -lsunwindow -lpixrect

