[Samba] See inherit user, need inherit group

[Paul Gienger]

> | The three inherit flags that are listed seem to work on
> | everything else but group membership.
> 
> This is a Unix thing.   Just set the group id bit on
> the parent directory (chmod g+s dir)

Yep, we've been running this way for a long time.  I investigated a bit more
and it looks like the users don't have a clue how to report a problem since
it works just fine.

/goingBackToMyCornerNow