Twenty Twelve: fix button active state to avoid a 2px shift, fixes #22825. Props ocean90.


git-svn-id: http://core.svn.wordpress.org/trunk@23426 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Twelve: remove unnecessary class values in posts navigation, fixes #23152. Props DrewAPicture.


git-svn-id: http://core.svn.wordpress.org/trunk@23427 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Twelve: clear center-aligned images properly. Fixes #23244.


git-svn-id: http://core.svn.wordpress.org/trunk@23428 1a063a9b-81f0-0310-95a4-ce76da25c4cd