Fix for running the FNIL demo.
Fix for running the FNIL demo.

The demo switches to high resolution near the end of the screen, so it
tries to output 501 lines.  This overflows the memory allocate to hold
the colour monitor RGB image.

Always allocate memory for 501 lines fixes the crash.  The demo looks
horrible, though.  But that's another matter, I think.

nocrew/ostis,nocrew/ostis,larsbrinkhoff/ostis,stefanberndtsson/ostis