title: How to add image logo with URL in vaadin
body: <p>I use vaadin 7.5.3 
  I want to add logo my web site page top with
  logo Url : <a href="http://...../example.png" rel="nofollow noreferrer">http://...../example.png</a></p>
  
  <p>But I want to read image on internet URL</p>