Commiting the rm_primary_group.patch posted on samba-technical

Commiting the rm_primary_group.patch posted on samba-technical

* ignore the primary group SID attribute from struct samu*
* generate the primary group SID strictlky from the Unix
  primary group when dealing with passdb users
* Fix memory leak in original patch caused by failing to free a
  talloc *
* add wrapper around samu_set_unix() to prevent exposing the create
  BOOL to callers.  Wrappers are samu_set_unix() and samu-allic_rid_unix()

git-svn-id: svn+ssh://svn.samba.org/data/svn/samba/branches/SAMBA_3_0@13679 0c0555d6-39d7-0310-84fc-f1cc0bd64818