fixes for ipv6 supported conntrack and libnetfilter_conntrack

[Yasuyuki KOZAKAI]

Hi, Pablo,

I played with your patches for IPv6 support to conntrack and
libnetfilter_conntrack. Please consider applying following fixes
on top of you patches.

[PATCH 1/2] conntrack: fix incomplete copying IPv6 addresses
[PATCH 2/2] conntrack: check address family mismatch
[PATCH 1/1] libnetfilter_conntrack: fix dumping IPv6 connections

Regards,

-- Yasuyuki Kozakai