In the past, we had lb config for both creating a configuration directory
and updating settings in there. With the rewrite in Python, we're now
changing this finally to the more sane 'init' (create initial 'sample'
configuration directory tree, taking most arguments that lb config did)
and 'config' which will only be a get/set program to work on top of
an already initialized configuration tree.

Stuffing bootstrapping of archive-keys for derivatives into lb_config, it's not a runtime thing and its logic should not be embedded in live-build but the config directory.