title: lazyLoadXT Background images add-on with multiple sources
body: <p>I'm using Jquery lazyLoadXT to load background images of specific DIV. I'm trying to have different SRC atributes, so it should load smaller images for mobile devices. </p>
  
  <p>This is the markup:</p>
  
  <pre><code>&lt;div class="img-container" data-bg="img/intro-00.jpg" data-bg-sm="img/intro-00-sm.jpg"&gt;&lt;/div&gt;
  
  &lt;script&gt;
      $.extend($.lazyLoadXT, {
        srcAttr: 'data-bkg-sm'
      });
  &lt;/script&gt;
  </code></pre>
  
  <p>Lazyload is working, but still loads the default image (data-bg). Is there an conflict between "srcAttr" and the background images add-on? Is there a workaround?</p>