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Original code by Rick Osborne, 2006
  http://cfdiff.googlecode.com/
... released under the Mozilla Public License v1.1
  http://www.mozilla.org/MPL/
... with an algorithm translated from the C-Sharp source by Matthias Hertel
  http://www.mathertel.de/Diff/
... which was originally released under the Creative Commins Attribution 2.0 Germany license
  http://creativecommons.org/licenses/by/2.0/de/
... and is based on a paper by Eugene Meyers
  Algorithmica Vol. 1 No. 2, 1986, p 251: "An O(ND) Difference Algorithm and its Variations"