Remove pointerup listener on controls

This PR suggests to remove the `pointerup` listener on controls an only keep the `click` listener.

The `pointerup` listener was added to workaround the 300ms tap delay on touch-based browsers but this delay is now gone (if the viewport meta is correct) on all browsers except iOS Safari.

For unsupported browsers (iOS Safari, old versions of Chrome, Firefox and native Android Browser), the [FastClick](https://github.com/ftlabs/fastclick) polyfill should be used.

See http://updates.html5rocks.com/2013/12/300ms-tap-delay-gone-away