Merge stable into default (NON-TRIVIAL) - dropping __future__ statement added by d2472948da9c - added migration from 407acc41beb5 to migration file for 3.16.1

<div id="ajaxroot">
  <div class="ajaxHtmlHead">
    <script src="http://foo.js" type="text/javascript"> </script>
  </div>
  <h1>Hello</h1>
</div>