tutorials: Renamed .org -> .orig

See http://www.openfoam.org/mantisbt/view.php?id=2076
  - .org is the file extension for emacs org-mode as well
  - .orig is more to the point (.org isn't always recognized as "original")
  - .original is too long, although more consistent with the convention
    of source code file naming

Update script contributed by Bruno Santos

tutorials/basic/potentialFoam/cylinder/Allrun

@@ -6,7 +6,7 @@ cd ${0%/*} || exit 1    # Run from this directory
 
 application=`getApplication`
 
-cp -r 0.org 0 > /dev/null 2>&1
+cp -r 0.orig 0 > /dev/null 2>&1
 runApplication blockMesh
 runApplication $application -withFunctionObjects -writePhi -writep
 runApplication streamFunction

tutorials/basic/potentialFoam/pitzDaily/Allrun

@@ -6,7 +6,7 @@ cd ${0%/*} || exit 1    # Run from this directory
 
 application=`getApplication`
 
-cp -r 0.org 0 > /dev/null 2>&1
+cp -r 0.orig 0 > /dev/null 2>&1
 runApplication blockMesh
 runApplication $application -writePhi -writep
 runApplication streamFunction