The comment screen hides the author column at narrow screen sizes; this adds back the author info above the comment content.

Merges [26961] to the 3.8 branch.

props SergeyBiryukov.
fixes #26618.


git-svn-id: https://develop.svn.wordpress.org/branches/3.8@26962 602fd350-edb4-49c9-b593-d223f7449a82