nx_match: add MFField parser

Signed-off-by: OHMURA Kei <ohmura.kei@lab.ntt.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
ofproto_v1_0: add nx_stats constants

Signed-off-by: OHMURA Kei <ohmura.kei@lab.ntt.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
ofproto_v1_0_parser: add nx_flow_stats_{request, reply}

Signed-off-by: OHMURA Kei <ohmura.kei@lab.ntt.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
lib ofctl_v1_2: add VLAN_ID setting means

This patch contains the following update for ofctl_v1_2 library.
 adding a means which sets up VLAN_ID.

 (I think that I will use this by a firewall Ryu application.)

Signed-off-by: TAKESHITA Noboru <takeshita.noboru@yes.nttcom.ne.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
of1.0: fix NXActionHeader typo

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
lib/packet/packet_base: fix signature of PacketBase.{parser, serialize}

All subclasses define them as
parser(cls, buf) and serialize(self, payload, prev)
Not parser(cls), serialize(self).

pylint also complains like
> W: 50,4:ipv4.parser: Arguments number differs from overridden method
> W: 65,4:ipv4.serialize: Arguments number differs from overridden method

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>