[ptx] clens

[dmg]

I have updated clens to take advantage of CreatePanorama. It would be
great if someone can try to compile it and run it.

Among the changes:

* Updated version to 0.3.1
* By default it uses the libpano library
* Added an option (--external or -e) to force the use of an external
  program (by default it is nona).
* I noticed that the clens script was using feathering, so I force a
  size = 0 for the feather.
* I added a check in the configure.ac for libpano (but I am not sure
  it works well, anybody with autoconf experience?)





--
Daniel M. German                  "Speak not about what you have read,
   Azerbaijani Proverb ->          but about what you have understood."
http://turingmachine.org/
http://silvernegative.com/
dmg (at) uvic (dot) ca
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