Enable flow actions in flow filter to modify packet.

Other changes:

  * Apply flow filters for outgoing packets when an unicast packet is
    broadcasted in the vBridge. In that case REDIRECT flow filter is
    ignored.

Change-Id: Id17cf857806f289b737a088af3f8c7dae27dc0f9
Signed-off-by: Shigeru Yasuda <s-yasuda@da.jp.nec.com>