packet lib: fix icmpv6.nd parser

Signed-off-by: HIYAMA Manabu <hiyama.manabu@po.ntts.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
tunnel_port_updater: g/c _LOCK

Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
vsctl: fix timeout

- run_command's timeout argument is named 'timeout_msec', but
  all callers seem to pass the value in second.  so rename
  the argument to 'timeout_sec'.

- gevent.Timeout takes a timeout value in second.
  remove a conversion, which seems wrong even if the argument was in ms.

Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
group quantum related options

caveats: no config file backward compat
add a threading hub module

it currently uses gevent or eventlet internally.
hub: stop trying import gevent

instead, allow to specify the type of hub by RYU_HUB_TYPE
environment variable.  make the default eventlet.
stop using gevent directly

uses to ryu.lib.hub instead.
change requirements: gevent -> eventlet
hub: add some unit tests