ofctl_v1_3: support metadata

Support metadata in FlowMod instructions and match.

both a decimal number and a hexadecimal number are able to use in 'metadata' and 'metadata_mask'.
all the following examples express the same flow entry.

flow = {'match': {'metadata': '12345/4095'},
        'actions': [{'type': 'WRITE_METADATA',
                     'metadata': '12345',
                     'metadata_mask': '4095'}]}

flow = {'match': {'metadata': '12345/4095'},
        'actions': [{'type': 'WRITE_METADATA',
                     'metadata': 12345,
                     'metadata_mask': 4095}]}

flow = {'match': {'metadata': '0x3039/0xfff'},
        'actions': [{'type': 'WRITE_METADATA',
                     'metadata': '0x3039',
                     'metadata_mask': '0xfff'}]}

Signed-off-by: Yuichi Ito <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
ofctl_v1_3: support meter

Support meter in FlowMod instructions and support MeterMod, MeterStats, MeterFeatures.

see following examples.

FlowMod with the meter instruction:

    flow = {'match': {},
            'actions': [{'type': 'METER',
                         'meter_id': 1}]
    curl -X POST -d '{"dpid": 1, "match": {}, "actions": [{"type": "METER", "meter_id": 1}]}' http://localhost:8080/stats/flowentry/add

MeterMod:

    meter = {'meter_id': 1,
             'flags': 'KBPS',
             'bands': [{'type': 'DROP',
                        'rate': 1000}]}
    curl -X POST -d '{"dpid": 1, "meter_id": 1, "flags": "KBPS", "bands": [{"type": "DROP", "rate": 1000}]}' http://localhost:8080/stats/meterentry/add

    NOTE: flags: 'KBPS', 'PKTPS', 'BURST', 'STATS'
          type: 'DROP', 'REMARK', 'EXPERIMENTER'

MeterStats:

    curl http://localhost:8080/stats/meter/1

MetetFeatures:

    curl http://localhost:8080/stats/meterfeatures/1

Signed-off-by: Yuichi Ito <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>