Add an admin API

Add an admin API endpoint to Nova.  This is intended to be an endpoint
only exposed internally to the deployment.  It will be used for
integration with other services, such as Cinder or Neutron.

By default, the admin API listens on port 35359.  When adding
information to the Keystone service catalog, this new port should be
used for the adminURL.

As of this commit, the API exposed by this endpoint is identical to that
of the regular API.  However, hooks are provided for adding admin API
endpoint specific API extensions.  This will be utilized in future
commits.

Implements blueprint admin-api

DocImpact

Change-Id: Ib9c22cd970d598b34618d9c91c779477aa1d4004
WIP: Add os-assisted-volume-snapshots extension
Eric's test rig, do not merge

test infra

test env stuff

testrig 1

Conflicts:
	nova/compute/manager.py

test setup

test fixup