In 3.5, we have chosen to de-emphasize the "attaching" part of the
post-attachment relationship. Existing functionality remains the same,
but UI emphasis is now placed on "parent" being where the item was
originally uploaded.
fixes#22439.
git-svn-id: https://develop.svn.wordpress.org/trunk@22630 602fd350-edb4-49c9-b593-d223f7449a82