Module transform_feedparser_data

This takes the feedparser tests from here:

  http://feedparser.org/tests/wellformed/sanitize/

and rewrites them to be easier to handle (not using the internal model
of feedparser).  The input format is::

  <!--
  Description: {description}
  Expect: {expression}
  -->
  ...
  <content ...>{content}</content>
  ...

The Expect expression is checked for
``entries[0]['content'][0]['value'] == {data}``.

The output format is::

  Description: {description}
  Expect: {expression} (if data couldn't be parsed)
  Options: 

  {content, unescaped}
  ----------
  {data, unescaped, if found}