Catch InstanceNotFound exceptions for V2 API instance_actions

Use the common.get_instance method to get the instance object
in the V2 API instance_actions extension rather than call
the compute api directly. The utility function
handes InstanceNotFound exceptions and tranlsates them to HTTPNotFound
rather than letting them propagate up causing a traceback.

Co-Authored-By: Michael Still <mikal@stillhq.com>

Change-Id: I1e69fed0c7c0c611fcfd48abbd4b4e0b1c8b403f
Closes-Bug: 1271146
Fix Jenkins translation jobs

The jobs nova-propose-translation-update and
nova-upstream-translation-update do not update from
transifex since our po files contain duplicate entries where
obsolete entries duplicate normal entries.

Remove all obsolete entries to fix the jobs.

Change-Id: I7f51922472f12f3a13feb71a6fb344076781d7e9
Closes-Bug: #1299349
Require admin context for interfaces on ext network

Currently any user can attach an interface to a neutron
external network, if the neutron plugin supports the port
binding extension.
In this case, nova will create neutron ports using the admin
client, thus bypassing neutron authZ checks for creating ports
on external networks.

This patch adds a check in nova to verify the API request has an
admin context when a request for an interface is made on a
neutron external network.

Change-Id: I5fb0bdcbf19eb82746ea3b192c1f65899bfb3c0b
Closes-Bug: 1284718
Merge "Catch InstanceNotFound exceptions for V2 API instance_actions"
Merge "Require admin context for interfaces on ext network"
Merge "Fix Jenkins translation jobs"