tree listing doesn't show revisions

not sure why i did that before, but it broke the tree listings
Merge branch 'v7.1' of git://github.com/phpwax/wildfire.content into v7.1

# By mikenosko
# Via mikenosko
* 'v7.1' of git://github.com/phpwax/wildfire.content:
  right src update for preview iframe
  create child now gets the right model