Class - UserLoginEvent

• UserLoginEvent.username:string - The username for the login attempt
• UserLoginEvent.user_id:string - Set this to the ID of the user, if the login was successful
• UserLoginEvent.reason:string - Sent to the client if reject was true
• UserLoginEvent.reject:bool - Whether to reject the login, for example invalid username
• UserLoginEvent.authenticated:bool - If the user was authenticated via the server. Can be overridden to force authentication.