colo-compare: Use IOThread to Check old packet regularly and Process pactkets of the primary

Remove the task which check old packet in the comparing thread,
then use IOthread context timer to handle it.

Process pactkets in the IOThread which arrived over the socket.
we use iothread_get_g_main_context to create a new g_main_loop in
the IOThread.then the packets from the primary and the secondary
are processed in the IOThread.

Finally remove the colo-compare thread using the IOThread instead.

Reviewed-by: Zhang Chen<zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Wang Yong <wang.yong155@zte.com.cn>
Signed-off-by: Wang Guang <wang.guang55@zte.com.cn>
Signed-off-by: Jason Wang <jasowang@redhat.com>
