
This patch adds per connection marks, and a target (CONNMARK)
respective a match (connmark) for using these.

Usage:

   connmark
       This  module  matches  the netfilter mark field associated
       with a connection (which can be  set  using  the  CONNMARK
       target below).

       --mark value[/mask]
              Matches  packets  in  connections  with  the  given
              unsigned mark value (if a mask is  specified,  this
              is logically ANDed with the mark before the comparison).


   CONNMARK
       This  is  used  to set the netfilter mark value associated
       with the connection

       --set-mark mark
              Set connection mark

       --save-mark
              Set connection mark to the same as the one  on  the
              packet

       --restore-mark
              Set  the  netfilter  packet  mark  value to the one
              associated with the connection. This is only  valid
              in the mangle table.
