[NETFILTER]: Add new iptables TTL target

This new iptables target allows manipulation of the TTL of an IPv4 packet.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc include/linux/netfilter_ipv4/ipt_TTL.h
Simple merge

diff --cc net/ipv4/netfilter/Kconfig
Simple merge

diff --cc net/ipv4/netfilter/Makefile
Simple merge

diff --cc net/ipv4/netfilter/ipt_TTL.c
Simple merge