We now no longer have the stupid --service-helper option, which silences
messages about already existing organisations, users or groups.
Instead of that option, we now have a new subcommand called
"process-json", which accepts a JSON file directly from the specified
NixOS module options and creates/deletes the users accordingly.
Note that this still has a two issues left to solve in this area:
* Deletion is not supported yet.
* If a user is created imperatively, the next run of process-json will
delete it once deletion is supported.
So we need to implement deletion and a way to mark organisations, users
and groups as "imperatively managed".
Signed-off-by: aszlig <aszlig@redmoonstudios.org>