ofctl_rest: fix some mistypes

In ryu/app/ofctl_rest.py found some mistypes. Error gets when using
stats/groupdesc/<dpid> and /stats/groupfeatures/<dpid>

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
bgp: bug fix of Multi Exit Discriminator (MED)

RyuBGP doesn't work well regarding the advertisement of BGP MED Attribute as follows.

(1) In spite of receiving BGP MED:"500" from iBGP(R2), RyuBGP can't advertise BGP MED:"100" to eBGP(R3).

    R1 -------------> R2 -------------> RyuBGP -------------> R3
       eBGP(MED:500)     iBGP(MED:500)    ^     eBGP(MED:500)
                                       (MED:100)

(2) When RyuBGP has received BGP MED:"200" from eBGP(R3), RyuBGP has sended BGP with missing-MED to iBGP(R2).
    As result, PolicyBaseRouting in R2(other RyuBGP) doesn't work properly becase of selecting wrong BestPath.

                   eBGP(MED:100)
    R1 ------------------------------------>+
                                            |
    R3 -------------> RyuBGP -------------> R2(RyuBGP) => Wrong result [BestPath is "R3-R2"]
       eBGP(MED:200)          iBGP(MED:N/A)

Signed-off-by: Toshiki Tsuboi <t.tsubo2000@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
test_ofctl_v1_2/3: Fix some test cases

UnitTest of the following cases had not been executed successfully.

{'dl_src/dst': "aa:bb:cc:11:22:33/*"}
{'eth_src/dst': "aa:bb:cc:11:22:33/*"}
{'nw_src/dst': "192.168.0.1/*", 'eth_type': 0x0800}
{'ipv4_src/dst': "192.168.0.1/*", 'eth_type': 0x0800}
{'arp_spa/tpa': "192.168.0.22/*", 'eth_type': 0x0806}
{'arp_sha/tha': "aa:bb:cc:11:22:33/*", 'eth_type': 0x0806}
{'ipv6_src/dst': '2001::aaaa:bbbb:cccc:1111/*', 'eth_type': 0x86dd}

This patch fixes this problem.

Signed-off-by: Minoru TAKAHASHI <takahashi.minoru7@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
test_ofctl_v1_2/3: Add a test case of masked metadata

Signed-off-by: Minoru TAKAHASHI <takahashi.minoru7@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
utils: Fix bytearray conversion

The parameter buf is an instance of bytearray, but Ryu tries to convert it as string,
and outputs the error messages as a result.
This patch fixes this problem.

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
test_utils: Add unit test for ryu.utils

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>