simplified html5 autofocus shim

simplified and reduced the [html5 autofocus shim](https://github.com/kkapsner/kkjs/blob/master/modules/kkjs.html5.js "kkjs.html5.js") by using `document.querySelectorAll()` like [here](http://forum.jswelt.de/tutorials-javascript/59859-html5-autofocus-fallback-f-r-unterst-tzende-browser.html "HTML5 Autofocus mit Fallback für nicht unterstützende Browser")