Allow users to define the seed that's used for manifest generation.
Regenerating an image with a given seed leads to the same manifest
(provided depsolving does the same).
The seed is normally mostly used to generate random filesystem UUIDs.
This will need a bunch of documentation in a follow up since the use
cases are meant to be advanced but it can really speed up multi-type and
rebuilds of the same image.
Signed-off-by: Simon de Vlieger <supakeen@redhat.com>
02461ac2a3