Improved tcp-intercept init script to configure also routing/iptables

Hello,

I have improved the init script provided with tcp-intercept to also configure by default the required routing and iptables rules.

The options can be customized via /etc/default/tcp-intercept.

It is also possible to disable the routing and iptables configuration of the init script by setting CONTROL_NETWORK=0 and CONTROL_IPTABLES=0 in /etc/default/tcp-interfept. This could be of interest if the administrator wishes to control iptables/network configuration in other scripts.

Regards,

Christian