Updates the featured image when the publish/update button is clicked (rather than instantly). Uses the existing post_thumbnail_meta_box() function. Does not remove the old featured image meta box JS, ajax handler, or CSS.
see #21776, #21390.
git-svn-id: https://develop.svn.wordpress.org/trunk@21770 602fd350-edb4-49c9-b593-d223f7449a82
3ef72a1dee