[Samba] Hide system users for wbinfo

[Robert Penz]

Hi! 

I've running an samba3 as domain controller and have also connected some 
linux machines with winbind. My problem now is that wbinfo shows all users 
on the linux server, even system users. How can I limit this to an range of 
user ids or only to users which can login? 

It specially looks bad on a suse standard install as the kdm shows all 
possible users. On kubuntu its not that bad as it doesn't show all possible 
users in the default setup.