Add temporary hooks for the widgets feature team to wp_widget_control().

props westonruter.
see #26661.

git-svn-id: https://develop.svn.wordpress.org/trunk@26865 602fd350-edb4-49c9-b593-d223f7449a82
Add comments for temporary hooks. see #26661.

git-svn-id: https://develop.svn.wordpress.org/trunk@26866 602fd350-edb4-49c9-b593-d223f7449a82