* removed the language attribute on the script element since it is obsolete and we...

* removed the language attribute on the script element since it is obsolete and we can safely omit it.
* make QRCode JS works with IE :
  * behave as a normal link if canvas aren't supported (<=IE8)
  * default parameter values in JS aren't widely supported (see: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Default_parameters ), use this method instead: http://stackoverflow.com/a/148918/1484919
  * dataset isn't supported in IE9 use getAttribute instead
  * addEventListener works with IE9+ and other browsers