filter-rewriter: introduce filter-rewriter initialization

filter-rewriter: introduce filter-rewriter initialization

Filter-rewriter is a part of COLO project.
It will rewrite some of secondary packet to make
secondary guest's tcp connection established successfully.
In this module we will rewrite tcp packet's ack to the secondary
from primary,and rewrite tcp packet's seq to the primary from
secondary.

usage:

colo secondary:
-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
-object filter-rewriter,id=rew0,netdev=hn0,queue=all

Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>