[Patch] add --as-sddl option to getntacl and create setntacl

[Matthieu Patou]

Matthias,

Find attached a patch for getntacl to add the --as-sddl option and a new 
program: setntacl that allow to set the security.NTACL attribute in 
command line.
This program can be useful for admins who wants to set NT ACL for files 
but without needing to time Windows adminstrator password.

This program could be also very useful to solve bug 5483 as we can use 
it during provision to set ACLs on policy files and dirs so that ACL in 
the AD and ACL on the files are in sync.

Any comment welcome !
Matthieu.