video and animator incremental download is sending every video and animator. client is excepted to receive a 401  if video and animator are not authorized. for now sending 404 becuase client is asking for a login repeatedly on receving 401. fix is to add a read_detail method which checks the ownership of the user.
Merge pull request #206 from digitalgreenorg/coco_incremental_bug

Sending 404 whenever client accesses any record which is unauthorized. Changes in Authorization classes.