for each task page
  grab page source, discard everything after the first ==section==.
Cache as $previous. Note $author.
  for each revision
    grab page source, discard everything after first ==section==.
Cache as $previous2. Note $author2
    compare $previous2 to $previous. If different, record $author to $list.
    replace $previous with $previous2
    replace $author with $author2