message: make clean removes ParaView output
diff: @@ -124,7 +124,7 @@ clean-build:
  clean-exec:
  @rm -f refined.mesh displaced.mesh mesh.* ex5.mesh
  - @rm -rf Example5* Example9* Example15* Example16* PVExample*
  + @rm -rf Example5* Example9* Example15* Example16* ParaView
  @rm -f sphere_refined.* sol.* sol_u.* sol_p.* sol_r.* sol_i.*
  @rm -f ex9.mesh ex9-mesh.* ex9-init.* ex9-final.*
  @rm -f deformed.* velocity.* elastic_energy.* mode_*
  