Comment form: Add HTML classes.
 * #respond gains .comment-respond
 * #reply-title gains .comment-reply-titlw
 * form gains .comment-form

props obenland.
see #23851.



git-svn-id: https://core.svn.wordpress.org/trunk@24525 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Thirteen: Update comment form selectors with new classes added in r24525.

props obenland.
fixes #23851.



git-svn-id: https://core.svn.wordpress.org/trunk@24526 1a063a9b-81f0-0310-95a4-ce76da25c4cd