Enable one disabled tests in NEC plugin that blocked by 1229954

Enable the disabled tests in NEC plugin that blocked by 1229954
https://github.com/openstack/neutron/blob/master/neutron
/tests/unit/nec/test_security_group.py#L64

Change-Id: Id15c5b431773d05f13201cdcd126ff2fa9f6aa06
Related-Bug: #1229954
Imported Translations from Transifex

Change-Id: Ibf9a7c3cdf6725807a2a3183937f0d8e99273744
Fix update_device_up method of linuxbridge plugin

Also add unit tests covering update_device_up and update_device_down
methods

Change-Id: I97f2f9249b684aa5350b3f0621754543e80bec70
Closes-Bug: #1241602
Merge "Enable one disabled tests in NEC plugin that blocked by 1229954"
Merge "Fix update_device_up method of linuxbridge plugin"
Merge "Imported Translations from Transifex"