There are a number of group-related problems that can only be solved by getting
the information as part of the logon. (The NETLOGON pipe User logon calls).
Currently, we ask for logon level 3, as we have done for ages.
Logon level 6 gives us back more group information, and saves us either trying
to figure it out the long way (more round trips) or not finding it out at all.
This would allow us to put more stuff into the NETLOGON cache.
i'll work on this one.