Use Element.matches if available

Spec:
http://dom.spec.whatwg.org/#dom-element-matches

Support in Chromium:
https://code.google.com/p/chromium/issues/detail?id=326652

Element.matchesSelector was never standardized and it is not available
in the most recent versions of Blink, Gecko, Presto, Trident or WebKit.
Merge pull request #2571 from foolip/matches-unprefixed

Use Element.matches if available