Merge: Apply serialization in calculator, a_star, more_collections, Couple and Container

Merge: Apply serialization in calculator, a_star, more_collections, Couple and Container

Use `auto_serialize` in the calculator example, and remove the old custom JSON serialization.

The `a_star` module needed special care and could not rely only on `auto_serialize`. This was to avoid serializing graphs as a deep tree, instead we serialize the nodes first, then the links and we rebuild the graph at deserialization.

Besides that, more collections support the serialization.

Pull-Request: #1364
Reviewed-by: Jean Privat <jean@pryen.org>
Reviewed-by: Alexandre Terrasa <alexandre@moz-code.org>
Reviewed-by: Lucas Bajolet <r4pass@hotmail.com>