Twenty Fourteen: accessibility fix for allowing the search button in the toolbar to be focused with the keyboard. Props joedolson and sabreuse, see #25054.

git-svn-id: https://develop.svn.wordpress.org/trunk@25613 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fourteen: remove unused images, following r25610. See #25300.

git-svn-id: https://develop.svn.wordpress.org/trunk@25614 602fd350-edb4-49c9-b593-d223f7449a82