* Fix a security hole that allowed a web user to edit images and other

* Fix a security hole that allowed a web user to edit images and other
  non-page format files in the wiki. To exploit this, the file already had
  to exist in the wiki, and the web user would need to somehow use the web
  based editor to replace it with malicious content.
  (Sorry Josh, this means you can't edit style.css directly anymore,
  although I do appreciate your fixes, actually..)