gpo: Initial commit for GPO work

gpo: Initial commit for GPO work

Enclosed is my Summer of Code 2013 patch to have vital password GPO always applied to the Samba4 Domain Controller using a GPO update service.

To try it out "make -j" your samba with the patch, apply a security password GPO and see the difference in ~20 seconds. It also takes GPO hierarchy into account.

Split from "Initial commit for GPO work done by Luke Morrison" by David Mulder

Signed-off-by: Garming Sam <garming@catalyst.net.nz>
Signed-off-by: Luke Morrison <luke@hubtrek.com>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>