message: FIX: RTK did not build with ITK 4.13
  fixed: LESS --> VERSION_LESS
diff: @@ -172,10 +172,10 @@ endif()
  list(APPEND RTK_INCLUDE_DIRS "${PROJECT_BINARY_DIR}")
  include_directories(${RTK_INCLUDE_DIRS})
  -if(ITK_VERSION LESS "4.4")
  +if(ITK_VERSION VERSION_LESS "4.4")
  include_directories(BEFORE utilities/itkImageScanlineConstIterator)
  endif()
  -if(ITK_VERSION LESS "4.5")
  +if(ITK_VERSION VERSION_LESS "4.5")
  include_directories(BEFORE utilities/itkBinShrinkImageFilter)
  endif()
  