Comment 53 for bug 857651

Add's a config file to /lib/... and /etc/...
Excluded= and MinimumUID config options.

MinimumUID in /etc overrides /lib. Exclude in /etc is combind with /lib

Add's an excluded property to the User type and the DBus handlers for manipulating this type

Admin users are not cached. Excluded users are still cached, but they are not returned by ListCachedUsers... I think the best thing would be to just add a new method such as ListGreeterUsers() and get the DMs to use this instead. Thoughts?