sweeping MR 12251 to 21.2

Tools/ART/ARTEnvironmentConfig.cmake

Tools/ART/CMakeLists.txt

Tools/ART/python/ART/__init__.py

Tools/ART/python/ART/art_base.py

Tools/ART/python/ART/art_build.py

Tools/ART/python/ART/art_grid.py

Tools/ART/python/ART/art_header.py

Tools/ART/python/ART/art_misc.py

Tools/ART/python/ART/art_rucio.py

Tools/ART/python/ART/docopt.py

Tools/ART/scripts/art-clean.py

Tools/ART/scripts/art-diff.py

Tools/ART/scripts/art-download.sh

Tools/ART/scripts/art-internal.py

Tools/ART/scripts/art-share.py

Tools/ART/scripts/art-task-build.sh

Tools/ART/scripts/art-task-grid.sh

Tools/ART/scripts/art.py