chainsaw: new extension for dangerous operations The first provided command is `chainsaw-update`, whose one and single job is to make sure that it will pull, update and purge the target repository, no matter what may be in the way (locks, notably), see docstring for rationale.

[build-system]
requires = ["setuptools", "wheel"]

[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true