cfg.modelChatUser: use CRUD model's ID === _id as id
cfg.modelChatUser: use CRUD model's ID === _id as id

* thus there's no need in extra config for disabling of
  saving items to backend

* this field will have 'statuser_id'
  4 chars status prefix:^^^^ hardcoded everywhere

olecom/enjsms,olecom/enjsms