Merge pull request #745 from commontk/fix-propagation-cmake-macosx-rpath

COMP: Ensure CMAKE_MACOSX_RPATH is passed to CTK inner-build

SuperBuild.cmake

@@ -50,6 +50,7 @@ ExternalProject_Add(${proj}
     -DCMAKE_CXX_FLAGS_INIT:STRING=${CMAKE_CXX_FLAGS_INIT}
     -DCMAKE_C_FLAGS_INIT:STRING=${CMAKE_C_FLAGS_INIT}
     -DCMAKE_INSTALL_PREFIX:PATH=${CMAKE_INSTALL_PREFIX}
+    -DCMAKE_MACOSX_RPATH:BOOL=${CMAKE_MACOSX_RPATH}
     ${ep_cxx_standard_arg}
   SOURCE_DIR ${CTK_SOURCE_DIR}
   BINARY_DIR ${CTK_BINARY_DIR}/CTK-build