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- Switch the config to ``pyproject.toml`` by default instead of ``flit.ini``,
and implement the PEP 517 API.
- A new option ``--pth-file`` allows for development installation on Windows
(where ``--symlink`` usually won't work).
- Normalise file permissions in the zip file, making builds more reproducible
across different systems.
- Sdists (.tar.gz packages) can now also be reproducibly built by setting
:envvar:`SOURCE_DATE_EPOCH`.
- For most modules, Flit can now extract the version number and docstring
without importing it. It will still fall back to importing where getting
these from the AST fails.
- ``flit build`` will build the wheel from the sdist, helping to ensure that
files aren't left out of the sdist.
- All list fields in the INI file now ignore blank lines (``requires``,
``dev-requires``, ``classifiers``).
- Fix the path separator in the ``RECORD`` file of a wheel built on Windows.
- Some minor fixes to building reproducible wheels.
- If building a wheel fails, the temporary file created will be cleaned up.
- Various improvements to docs and README.