[ptx] automatch some more progress

[Bruno Postle]

I've made some more changes to my automatch perl script for
generating control points:

   http://bugbear.blackfish.org.uk/~bruno/distance/Match-Image-0.02.tar.gz

-  There is now a README file with instructions.

-  It's quite a lot faster and scales better (~30 minutes to match
   14 images).

-  It simply refuses to find corellations between about a third of
   all image pairs - I'm not sure if this is a fundamental drawback
   of the technique or some bug in my code.

-- 
Bruno