Element.requestFullscreen()

Pushes support back to IE11.

/**
 * Element.requestFullScreen() polyfill
 * @author Chris Ferdinandi
 * @license MIT
 */
if (!Element.prototype.requestFullscreen) {
	Element.prototype.requestFullscreen = Element.prototype.mozRequestFullscreen || Element.prototype.webkitRequestFullscreen || Element.prototype.msRequestFullscreen;
}