Improved version of generator

This version use a generating algorithm to ensure
the generator constraints. It has two new options:
- s=N to shuffle or sort the result
- p=N to set the percentage of modification rules

The Makefile now make optimisation and have warning detection.

The make_policies script now use the shuffle option.

Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>