Twenty Ten and Twenty Eleven: revert r23720 and r23721 (closes #23772) and r23718 and r23719 (closes #23774).

Unfortunately, it's too late for these improvements in older themes since it's very likely they'll adversely affect child themes.

git-svn-id: http://core.svn.wordpress.org/trunk@23778 1a063a9b-81f0-0310-95a4-ce76da25c4cd