* Implement symlinks
* Initfs only has links with absolute paths.
* Relative links are assumed to be relative to link location.
* Absolute paths must point into the archived location. E.g. if we
archive /home/foo/data and wish the resultant link to point to
/scheme/rand, then the absolute link must be
/home/foo/data/scheme/rand.
* Move archive_common to a crate within the workspace -- Rust doesn't
seem to accept #[path(..)] attributes with `..` segments anymore so
tests wouldn't build on my machine.
* Improve the test to assert complete filesystem structure.
* Bump to edition 2021
* cargo fmt & clippy
Kamil Koczurek