This ensures that the gid's for the auto-generated user groups stay in
sync with the gid in /etc/passwd. It also makes it easier to evolve the
format of /etc/group in the future.

This allows redirecting the location packages are installed using
symlinks. This makes it much easier to change the filesystem hierarchy
by not having to change every recipe in the cookbook.

This fixes completing the image build on gentoo and MacOS.

This enables flexible cross-installation of packages as opposed to only
compiling for the x86_64-unknown-redox target.

This also permits native builds.

I sorta OOP'ed this, combining the logic of what needs to happen for
each config object with those objects. More things are coming, this is a
very WIP commit.