respect style from best practices. this makes the code a lot easier to
read.
also change groups from "root" to "0" to make them more portable (e.g.
in freebsd, the admin group is "wheel" but has gid "0")
this allows us to simplify the manifests by using:
extra-access { 'user': }
.. instead of having to explicitely set it.
if we need to have multiple users, we can do:
extra-access { 'user_foo': name => 'user' }
