message: cmake: add BUILD_APPS_LIST
  build "opencv_version" only: `cmake -DBUILD_APPS_LIST=version ...`
  option 'BUILD_opencv_apps' should be 'ON'
diff: @@ -3,9 +3,22 @@ add_definitions(-D__OPENCV_APPS=1)
  link_libraries(${OPENCV_LINKER_LIBS})
  -add_subdirectory(traincascade)
  -add_subdirectory(createsamples)
  -add_subdirectory(annotation)
  -add_subdirectory(visualisation)
  -add_subdirectory(interactive-calibration)
  -add_subdirectory(version)
  +macro(ocv_add_app directory)
  + if(DEFINED BUILD_APPS_LIST)
  + list(FIND BUILD_APPS_LIST ${directory} _index)
  + if (${_index} GREATER -1)
  + add_subdirectory(${directory})
  + else()
  + message(STATUS "Skip OpenCV app: ${directory}")
  + endif()
  + else()
  + add_subdirectory(${directory})
  + endif()
  +endmacro()
  +
  +ocv_add_app(traincascade)
  +ocv_add_app(createsamples)
  +ocv_add_app(annotation)
  +ocv_add_app(visualisation)
  +ocv_add_app(interactive-calibration)
  +ocv_add_app(version)
  