Revert "change response codes to 404, seems more accurate."

While 404's are more accurate, I experienced browser performance issues.
Particularly in chrome where pages would attempt to make the same javascript
request over and over, at a feverish pace.  Switched back to 200 response
and the problem goes away.

This reverts commit bae13e9844825d6f5240fae9e4e43f9217d6cade.