message: ex6p: added one more -cs run
diff: //
  // Sample runs: mpirun -np 4 ex6p -m ../data/star-hilbert.mesh -o 2
  // mpirun -np 4 ex6p -m ../data/square-disc.mesh -rm 1 -o 1
  -// mpirun -np 4 ex6p -m ../data/square-disc.mesh -rm 1 -o 2
  // mpirun -np 4 ex6p -m ../data/square-disc.mesh -rm 1 -o 2 -h1
  +// mpirun -np 4 ex6p -m ../data/square-disc.mesh -rm 1 -o 2 -cs
  // mpirun -np 4 ex6p -m ../data/square-disc-nurbs.mesh -o 2
  // mpirun -np 4 ex6p -m ../data/fichera.mesh -o 2
  // mpirun -np 4 ex6p -m ../data/escher.mesh -rm 2 -o 2
  