Polyfill matches DOM method (depends on querySelectorAll)

matches.js

/* improved version of the one found at https://developer.mozilla.org/docs/Web/API/Element/matches */
(function(p) {
	if (p.matches) return;
	p.matches =
		p.matchesSelector ||
		p.mozMatchesSelector ||
		p.msMatchesSelector ||
		p.oMatchesSelector ||
		p.webkitMatchesSelector ||
		function(s) {
			var matches = (this.document || this.ownerDocument).querySelectorAll(s),
				i = matches.length;

			while (--i >= 0 && matches.item(i) !== this) { /* */ }
			return i > -1;
		};
}(Element.prototype));