Twenty Fourteen: partial revert of r26558 to avoid blocking access to the Menu Toggle in IE when in small viewports. See #26189 and #26379.

git-svn-id: https://develop.svn.wordpress.org/trunk@26661 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fourteen: rework "current menu" submenu icons to use Genericons for simplicity and to inherit colors better. Props celloexpressions, fixes #26424.

git-svn-id: https://develop.svn.wordpress.org/trunk@26662 602fd350-edb4-49c9-b593-d223f7449a82