r9952: Adapt better to the Windows way of taking and assigning ownership:

r9952: Adapt better to the Windows way of taking and assigning ownership:

* Users with SeRestorePrivilege may chown files to anyone (be it as a
backup software or directly using the ownership-tab in the security
acl editor on xp), while

* Users with SeTakeOwnershipPrivilege only can chown to themselves.

Simo, Jeremy. I think this is correct now.

Guenther
(This used to be commit 1ef7a192eed457d302a08c692bb54a73a1af4afd)