title: html2canvas, proxy to read facebook images
body: <p>I am trying to use the html2canvas to render a img from a div, which contains some images, and they could be or not from facebook servers, but I don't know how to use the proxy option for this purpose.
  Here's my html code and js code:</p>
  
  <pre><code>&lt;div class="layout show" id="layout_2"&gt;
    &lt;div class="quadro two ui-droppable" data-id="105" style="background-image: url(http://www.fotoclub.com.br/css/capas/loading.gif);"&gt;
      &lt;img src="https://fbcdn-sphotos-d-a.akamaihd.net/hphotos-ak-ash4/1395770_689674961065927_34713189_n.jpg" class="two"&gt;
    &lt;/div&gt;
    &lt;div class="quadro two ui-droppable" data-id="109" style="background-image: url(http://www.fotoclub.com.br/css/capas/loading.gif);"&gt;
      &lt;img src="https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-frc1/1424485_689674991065924_420503222_n.jpg" class="two"&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>JS:</p>
  
  <pre><code>html2canvas($("#layout_2"), {
      onrendered: function(canvas_) {
          var canvas_div = document.getElementById("canvas_div");
          canvas_div.appendChild(canvas_);
      }
  });
  </code></pre>
  
  <p>Then I have this div with the "canvas_div" ID down on page.</p>