NativeFileDialogs

-Needed to change nfd_cocoa to an objc++ file with mm extension

Engine/lib/nativeFileDialogs/CMakeLists.txt

@@ -5,7 +5,7 @@ set(TORQUE_NFD_COMMON_SOURCES "${TORQUE_NFD_ROOT}/nfd_common.c")
 set(TORQUE_NFD_INCLUDE_DIRECTORIES "${TORQUE_NFD_ROOT}" "${TORQUE_NFD_ROOT}/include")
 
 if (APPLE)
-  set(TORQUE_NFD_SOURCES ${TORQUE_NFD_COMMON_SOURCES} "${TORQUE_NFD_ROOT}/nfd_cocoa.m")
+  set(TORQUE_NFD_SOURCES ${TORQUE_NFD_COMMON_SOURCES} "${TORQUE_NFD_ROOT}/nfd_cocoa.mm")
 elseif (UNIX)
   if (TORQUE_USE_ZENITY)
     set(TORQUE_NFD_SOURCES ${TORQUE_NFD_COMMON_SOURCES} "${TORQUE_NFD_ROOT}/nfd_zenity.c")