niti: Adapted bin_and/or/xor for Int in niti.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
Merge: niti: Adapted bin_and/or/xor for Int in niti.

Just added a few methods to niti that weren't implemented yet.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>

Pull-Request: #552
Reviewed-by: Jean Privat <jean@pryen.org>
Reviewed-by: Alexis Laferrière <alexis.laf@xymus.net>