Nix expressions provide all the features that Quilt series files have,
so using those instead is pointless. Also, lib.readPathsFromFile
(the function used to read series files) has the following warning:
> NOTE: This function is not performant and should be avoided.
This also removes some orphaned series files, and unused references to
copyPathsToStore (which were probably missed in previous commits
where calls to lib.readPathsFromFile were removed)
After making `ffmpeg` point to the latest `ffmpeg_4`, all packages that
used `ffmpeg` without requiring a specific version now use ffmpeg_3
explicitly so they shouldn't change.
- Reduce environment pollution with a separate $bin output containing programs,
plugins, and shared data. Libraries remain in $out and are not installed into
the environment.
- Only propagate build inputs as required.
