RestController - move custom callbacks to repository

[benedyktdryl]

/* kind of magic - move to repo */
    private function doCustomActions(&$model)
    {
        foreach ($model->customCallbacks as $action) {
            if(method_exists($this, $action)) {
                call_user_func_array(array($this, $action), array(&$model));
            }
        }
    }

    /* move this to service or something */
    private function setCurrentUser(&$model)
    {
        $model->setUser($this->getCurrentUser());
    }