[Samba] ACL not set from Microsoft

[Miguel Medalha]

Please note that a new vfs_acl_xattr parameter was also later introduced 
(see "man vfs_acl_xattr"):

acl_xattr:default acl style = [posix|windows]
            This parameter determines the type of ACL that is synthesized in
            case a file or directory lacks an security.NTACL xattr.

            When set to posix, an ACL will be synthesized based on the POSIX
            mode permissions for user, group and others, with an 
additional ACE
            for NT Authority\SYSTEM will full rights.

            When set to windows, an ACL is synthesized the same way Windows
            does it, only including permissions for the owner and NT
            Authority\SYSTEM.

            The default for this option is posix.