* guix/scripts/pack.scm (squashfs-image)[database]: New variable.
[build]: Add (gnu build install) to the closure. Call
'install-database-and-gc-roots' when DATABASE is true, and invoke
mksquashfs once more.
* tests/pack.scm ("squashfs-image + localstatedir"): New test.
* guix/docker.scm (build-docker-image): Add #:database parameter.
Create /var/guix/db, /var/guix/profiles, etc. when DATABASE is true.
* guix/scripts/pack.scm (docker-image): Export. Remove #:deduplicate?
parameter. Define 'database' and pass it to 'docker-image'.
* tests/pack.scm (test-assertm): Recompile the derivation of
%BOOTSTRAP-GUILE.
("docker-image + localstatedir"): New test.