Twenty Thirteen: fix comment author styles to only add star icon to the post author's comment(s). Fixes #24281.

git-svn-id: http://core.svn.wordpress.org/trunk@24197 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Avoid warning in gallery_shortcode() when called outside of post context.

Props kovshenin
fixes #24272


git-svn-id: http://core.svn.wordpress.org/trunk@24198 1a063a9b-81f0-0310-95a4-ce76da25c4cd