Twenty Fourteen: Apply `max-width` values to avoid site title breaking the layout in small screens. Props sixhours, rclations. See #28237.

git-svn-id: https://develop.svn.wordpress.org/trunk@28691 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fourteen: update to Genericons 3.0.3. Props celloexpressions, closes #28456.

git-svn-id: https://develop.svn.wordpress.org/trunk@28692 602fd350-edb4-49c9-b593-d223f7449a82