Adding css3-mediaqueries.js and html5.js to head

Two fallback scripts via CDN.

— css3-mediaqueries.js
Provides media-queries support (< IE9)
https://code.google.com/p/css3-mediaqueries-js/

— html5.js
Provides HTML5 semantics support (< IE9)
https://code.google.com/p/html5shiv/