Make sudo, init prebuild, build and Prepare fields lists and only
concatenate them with '; ' before execution. This allows arbitrary
commands inside the fileds (even && and ';') as we don't need to split
the commands again for rewritemeta.
- Update usage documentation.
- Use argparse.
- Simplify config handling (similar to readmeta.py).
- Drop code for fdroidserver before 0.7.0.
- Reformat with black.
This requires manually running it. I suppose it would be possible to
include a snapshot of the dumped internal representation for each release,
then make the tests run automatically against that. Right now, the dump is
17megs of YAML. Seems large to include in this git repo.
