Add active class for useful rating for styling

Hi all

We need a feature relate to Useful rating. For now, we have this markup

<div class="useful-rating">
<a href="#"><i class="fa fa-thumbs-down"></i></a>
<a href="#"><i class="fa fa-thumbs-up"></i></a>
</div>

for both useful and un-useful case. I think it should be better if we have active class for each case.