uploaded reference PNG for spXCF

[Lofton Henderson <lofton@rockynet.com>]

All --

I have used Benoit's script equivalent, along with screen capture and Adobe 
ImageReady (crop and saveas PNG), to create a reference image for the spXCF 
test:  spXCF.png

Also #1:  I renamed his spXCF2.htm to spXCF-refpic.htm, and put in a little 
comment header explaining what it is for.

Also #2:  Suggestion for spXCF.cgm...  The wheel assembly in the upper 
right quadrant is drawn with line type -4, and LETD defines a "difficult" 
type for -4 -- basically a dashed line with equal length on and off 
segments, but the duty-cycle-length is about 1/500 of VDC Extent.  I.e., 
each 'on' segment and each 'off' segment are about 1/1000 of VDC 
extent.  I.e., the on-off cycle is on the order of 1 pixel.  In some 
viewers you can see it if you zoom enough.  But to the casual observer, it 
looks solid.  Since the result of the button is "change to solid" ... it 
would be best to have a more distinct initial view.

Benoit (or anyone) ... could you add that improvement to your queue?

This finishes my action item for now.

-Lofton.