Correctly display currently checked radio button on Android, too (4.3/4....

While with the last changes the model for radio buttons gets updated correctly on Android, there was still a weird display issue (tested on 4.3 and 4.1).

This seems to be related to a bug on Android discussed e.g. at http://css-tricks.com/forums/topic/checkbox-hack-on-mobile-webkit/:
> Sibling (~) and adjacent sibling(+) combinators work the same on the default Android browser – they each only pick up the NEXT SIBLING when used in conjunction with a pseudo class

This is what works for me on all devices (including iOS). I also included a possibilty to have a name for the radio.