message: Treat includes as system headers for Axom's third party libraries
  This disables warnings generated when compiling these files for compilers that support this feature.
  Added now to disable a warning (-Wno-cast-function-type)
  about how mfem casts function pointers in its Coefficient class.
  Suggested by Chris White.
diff: @@ -23,10 +23,12 @@ if (CONDUIT_DIR)
  include(cmake/thirdparty/FindConduit.cmake)
  blt_register_library( NAME conduit
  INCLUDES ${CONDUIT_INCLUDE_DIRS}
  - LIBRARIES conduit)
  + LIBRARIES conduit
  + TREAT_INCLUDES_AS_SYSTEM ON)
  blt_register_library( NAME conduit_relay
  INCLUDES ${CONDUIT_INCLUDE_DIRS}
  - LIBRARIES conduit_relay)
  + LIBRARIES conduit_relay
  + TREAT_INCLUDES_AS_SYSTEM ON)
  else()
  message(STATUS "Conduit support is OFF")
  endif()
  @@ -39,7 +41,8 @@ if (HDF5_DIR)
  include(cmake/thirdparty/SetupHDF5.cmake)
  blt_register_library( NAME hdf5
  INCLUDES ${HDF5_INCLUDE_DIRS}
  - LIBRARIES ${HDF5_LIBRARIES} )
  + LIBRARIES ${HDF5_LIBRARIES}
  + TREAT_INCLUDES_AS_SYSTEM ON)
  else()
  message(STATUS "HDF5 support is OFF")
  endif()
  @@ -52,7 +55,8 @@ if (MFEM_DIR)
  include(cmake/thirdparty/FindMFEM.cmake)
  blt_register_library( NAME mfem
  INCLUDES ${MFEM_INCLUDE_DIRS}
  - LIBRARIES ${MFEM_LIBRARY} )
  + LIBRARIES ${MFEM_LIBRARY}
  + TREAT_INCLUDES_AS_SYSTEM ON)
  else()
  message(STATUS "MFEM support is OFF")
  endif()
  @@ -85,7 +89,8 @@ if (SCR_DIR)
  include(cmake/thirdparty/FindSCR.cmake)
  blt_register_library( NAME scr
  INCLUDES ${SCR_INCLUDE_DIRS}
  - LIBRARIES ${SCR_LIBRARY} )
  + LIBRARIES ${SCR_LIBRARY}
  + TREAT_INCLUDES_AS_SYSTEM ON)
  else()
  message(STATUS "SCR support is OFF")
  endif()
  