updated change method to return args

Made a change so that the onChange now provides an additional param of the element, similar to select, making it possible to do a live color select using the actual element instead of relying on a dom request.

ie.
 
$('.colorSelector').ColorPicker({
  onChange : function(hsb, hex, rgb, el) {
     $(el).find('div').css('backgroundColor', '#' + hex);
     $(el).val(hex);
     $(el).data( hex );
  }
});
Merge pull request #8 from ss44/patch-1

updated change method to return args