bundlespec: make the `stream` case less special The handling of the stream case seems fragile (does not account for newer parts and options that will arise) and has special code dedicated to it. To simplify and strengthen things, we make it use the same mechanism as the other options. So we make it less special by making it a special value in the common case.

[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