isJoinNotified -- Checks if a member receives new recruit notices.
This function checks whether the member with id specified by $pin is on the recruit notification list. This is the only check made, so what games the notification is for has no bearing on this function's return value.
This function returns true if the member receives notices, and false otherwise. This function returns false on failure.
isJoinNotified (1) /* Returns true if member with id 1 receives join notifications for any game. Returns false otherwise. */