Log Message:
pkgin-0.5.2
        Various minor fixes from NetBSDfr hackathon
        Moved break_depends() at the end of impact.c to avoid inconsistencies
        Check for real filesystem size to be occuppied by upgrade
        Check for user permissions before update_db
        update_db() returns a status so we can warn simple users
        introduced have_enough_rights(), fixed pkg_keep() perms
        Various return codes fixed to satisfy frontends