Fixed jQuery bug/enahnced jQuery to not blindly convert anything that's not a string...

Fixed jQuery bug/enahnced jQuery to not blindly convert anything that's not a string to an integer and append 'px', resulting in values like "nullpx" and "NaNpx" which would cause errors in Internet Explorer. Now we are using ( parseInt( size ) || 0 ) + "px" so that if size is null or NaN it will be converted to 0. I've also passed this upstream (dev.jquery.com/ticket/7116)