Twenty Thirteen: search form fixes for IE7, and add fallback search type selector to RTL stylesheet, see r23961. Closes #23997.

git-svn-id: http://core.svn.wordpress.org/trunk@24035 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Thirteen: remove toolbar callback in functions.php -- and add an `!important` in its place in the stylesheet. Props obenland, fixes #24129.

git-svn-id: http://core.svn.wordpress.org/trunk@24036 1a063a9b-81f0-0310-95a4-ce76da25c4cd