Recognized interactive users as any user

Recognized interactive users as any user

Since Vista, the standard directory /Users/Public which should be accessed
by any user is actually restricted to a few group of users, among them
the interactive ones. To make this directory accessible without using
the Posix ACLs, all Linux users are considered as interactive.
However, when Posix ACLs are used, users supposed to be interactive have
to be put into a secondary group mapped to the equivalent Windows group.