title: Access dropzoneJS file's temporary source
body: <p>I'm using dropzone js in my website and I'd like to access the dropped photo's source used by the plugin. Here's what I mean: within the <code>added file</code> event listener I can easily access the dropped file's name, like  </p>
  
  <pre><code>dropzoneForm.on('addedfile', function(file){
        console.log(file.name);
      });  
  </code></pre>
  
  <p>but looking around within the <code>file</code> object, I can't get the image source used by the plugin to provide the preview. Checking the DOM tree, I did find the <code>.dz-image</code> section, with the image's source used in the preview:  </p>
  
  <pre><code> &lt;div class="dz-image"&gt;
    &lt;img data-dz-thumbnail="" 
      alt="Profilo-Facebook.jpg"
      src="data:image/png;base64,iVBORw0...anN6CQAAAABJRU5ErkJggg=="&gt;  
  </code></pre>
  
  <p>So, somewhere the file's name is stored as well as the temp source used by the plugin.<br>
  Now, here's my question: how can I access the file source the same way I can access the file name? The purpose is to use the source to populate a second table (I'm using angularJS). I did try several ways to get a <code>source</code> attribute but I keep getting back <code>undefined</code>.<br>
  I.e.  </p>
  
  <pre><code>dropzoneForm.on('addedfile', function(file){
        console.log(file.source); // or src, or whatever
      });  
  </code></pre>
  
  <p>doesn't work.<br>
  Any help will be greatly appreciated. Thanks. </p>