Merge: lib fix warnings (ai)

Some more fixes on warnings.

This time, this is the `ai` project that ends up cleaned of all warnings!

Pull-Request: #1007
Reviewed-by: Jean Privat <jean@pryen.org>
Reviewed-by: Alexis Laferrière <alexis.laf@xymus.net>
Reviewed-by: Lucas Bajolet <r4pass@hotmail.com>