BUG: correct ITK review variable name



git-svn-id: https://svn.bigr.nl/elastix/trunkpublic@4287 4d348492-3962-11de-aa85-65a2020054a3
ENH: clarified external component names



git-svn-id: https://svn.bigr.nl/elastix/trunkpublic@4288 4d348492-3962-11de-aa85-65a2020054a3