Don't use connection tracking for loopback traffic.
firewall: ipv6: Discard all packets with rounting header of type zero.

RFC 5095
firewall: Add global ICMP filter table.
firewall: Add kernel initialization.

When the network/firewall is started, prior to that the
firewall-kernel-init script is started that loads our
configuration into the kernel.

The static sysctl configuration files are removed to
be able to configure some of the options.
firewall: Re-unity firewall6/4 configuration again.