title: Formdata object shows empty even after calling append
body: <p>Append in formdata Object shows empty.</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
  &lt;head&gt;
  &lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.2/jquery.min.js"&gt;&lt;/script&gt;
  &lt;script&gt;
  $(document).ready(function(){
      $("button").click(function(){
          var formy = new FormData();
          formy.append("file", $("#file")[0].files[0]);
          console.log(formy);
  });
  });
  &lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;input id="file" type="file" size="40"&gt;&lt;br&gt;&lt;br&gt;
  &lt;button&gt;Send an HTTP POST request to a page and get the result back&lt;/button&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>The output of the above code in the console log gives me</p>
  
  <pre><code>Formdata{}
  append:function append()
  arguments:null
  caller:null
  length:2
  name:"append"
  </code></pre>
  
  <p>whereas <code>console.log($("#file")[0].files[0])</code> gives me File <code>{name: "document.pdf", lastModified: 1462959300000, lastModifiedDate: Wed May 11 2016 15:05:00 GMT+0530 (IST), webkitRelativePath: "", size: 5275…}</code></p>
  
  <p>Why is append for formdata not working?</p>