Metadata in `setup.cfg` rather than `pyproject.toml` as I'm a bit confused
about `setuptools` support for PEP-621.
Test stuff still in `setup.py`, this needs updating and I'm not satisfied with
the way they are loaded/discovered.
- Fixes zip downloads failing when zipping enough data that Zip64
extensions are required by automatically enabling them if needed.
- Fixes zip downloads failing when a file has a datestamp that zipfiles
cannot store (pre-1980 or post-2108) by clamping them within the
supported range.
- Massively speeds up zip downloads by disabling compression (audio
files generally don't compress well anyway)
- Computes the total size of a generated zip file before streaming it
and sets the `Content-Length` header. This allows clients to show a
final size and progress bar while downloading, as well as detect if
the download fails.
- Adds a check to prevent sending an empty zip file to the client if
there was no content to download (will error out instead).
- `os.scandir` (provided by a 3rd party package in 2.7)
- `os.replace` (doesn't exist in 2.7 - have to use `os.rename` instead)
- `os.utime` (the times param is required in 2.7)
