This patch introduces a new flag called IPS_PICKUP that forces the 
protocol handler to pick up the required information in order to ensure 
that the connection will reach a successful state.

Two new ctnetlink attributes are also introduced to inject the window 
scale factor since TCP window tracking could need it to take over the 
connection properly.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

-- 
The dawn of the fourth age of Linux firewalling is coming; a time of 
great struggle and heroic deeds -- J.Kadlecsik got inspired by J.Morris