writing custom query set

@mattdrayer @martynjames In users api I have added the ability to lookup by anonymous user id if `id` is not integer. It will support SLNS-63.
@mattdrayer The correct hash for discussion is: 62d9c2d5c8bbad079f904f09f1094f71b0bab391. For ooyala, I need to update it anyway soon. The new needed hash is: 2072409e296bccd3fbe2fa9e64009c5cb5cda30c