Bug 1003843 - Follow up to Bug 951676 - [Messages][Refresh] Add specific image in case of more than one recipient in the list threads. r=schung

That's probably more precise than relying on ```window.innerWidth```+ some magic number, but looks a bit complicated and I had to add node to the dom before calling ```setContact``` (though I think on phone node will be already in DOM when contact search callback is fired..) to make ```getBoxQuads``` works. 

What do you think?