val print : Config.config -> Gwdb.base -> Gwdb.person -> unit
(** Displays the menu that lists all person's relatives depending on ancestor and his descandant levels
    specified by [conf.env] variables {i v1} (for ancestor) and {i v2} for his descandant. For exemple :

    "v1" = 1, "v2" = 1 - Displays all person's siblings (mount to the person's parent (ancestor of level 1)
                     and lists all his children (descandant of level 1));
    "v1" = 2, "v2" = 2 - Displays all cousins;
    "v1" = 2, "v2" = 1 - Displays all uncles/aunts;
    "v1" = 1, "v2" = 2 - Displays all nieces/nephews;
    etc.

    Variable "t" is used to display anniversaries for relatives like [BirthdayDisplay.gen_print].
    If nor of those variables are defined, prints menu that allows to access the most common relatives (except for direct relatives)
    like cousins, siblings, uncles/aunts, etc. *)
