title: using dropzone.js mock file outside init returns dropzone.emit as not defined
body: <p>when i use this code below inside dropzone's init it works perfectly fine:</p>
  <pre><code>var existingFiles = [
          { name: &quot;Filename 1.pdf&quot;, size: 12345678 },
          { name: &quot;Filename 5.pdf&quot;, size: 12345678 }
      ];
  
      for (i = 0; i &lt; existingFiles.length; i++) {
          myDropzone.emit(&quot;addedfile&quot;, existingFiles[i]);
          myDropzone.emit(&quot;complete&quot;, existingFiles[i]);                
      }
  </code></pre>
  <p>but when i try to use it in a onclick event which includes an ajax response it causes an unexpected error stating &quot;myDropzone.emit is not a function&quot;</p>
  <p>sample code of ajax response:</p>
  <pre><code>success: function(data){
      $.each(JSON.parse(data), function(key,value) {
          var mockFile = { name: value.name, size: value.size };
          myDropzone.emit(&quot;addedfile&quot;, mockFile);
          myDropzone.emit(&quot;thumbnail&quot;, mockFile, value.path);
          myDropzone.emit(&quot;complete&quot;, mockFile);
          //alert(&quot;++&quot;);
      });
  },
  </code></pre>