ENH: Added option CTEST_USE_LAUNCHERS to the CTK-Configure superbuild step.

See http://kitware.com/blog/home/post/11

SuperBuild.cmake

@@ -296,6 +296,7 @@ ExternalProject_Add(${proj}
   CMAKE_ARGS
     ${ctk_superbuild_boolean_args}
     -DCTK_SUPERBUILD:BOOL=OFF
+    -DCTEST_USE_LAUNCHERS:BOOL=${CTEST_USE_LAUNCHERS}
     -DCMAKE_INSTALL_PREFIX:PATH=${ep_install_dir}
     -DCMAKE_BUILD_TYPE:STRING=${CMAKE_BUILD_TYPE}
     -DQT_QMAKE_EXECUTABLE:FILEPATH=${QT_QMAKE_EXECUTABLE}