Make the adduser commands copy-pasteable.

YOURUSER==$(whoami), and copy-paste is easier than interpreting by
hand.

Change-Id: Ia17d13045517e8007db3afe8ff0eedf36019b2df
Make config updates work with rebased branches.

Derived infrastructure deployments may well live as a set of rebased
patches floating on the upstream infrastructure. Simple 'pull -q' will
conflict if the reference branch is rebased.

Change-Id: I8127bb6305208879957c01e1c81b6329d74b27bf