CLI for creating/activating policy from library

[Eric K]

API reference:
https://github.com/openstack/congress-specs/blob/master/specs/pike/policy-library.rst#policy-engine-methods

Workflow reference:
https://github.com/openstack/congress-specs/blob/master/specs/pike/policy-library.rst#support-for-using-policies-from-the-library

Depends-on: https://bugs.launchpad.net/congress/+bug/1693617

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/479167
Committed: https://git.openstack.org/cgit/openstack/congress/commit/?id=94fdc38c867a9b5dd7cd28f77c64a6fa973336d9
Submitter: Jenkins
Branch: master

commit 94fdc38c867a9b5dd7cd28f77c64a6fa973336d9
Author: Eric Kao <email address hidden>
Date: Sun Jun 25 14:45:37 2017 -0700

    Add policy creation with rules or from policy library

    persistent_create_policy_with_rules method added to agnostic runtime
    to transactionally create policy along with rules. The main work is
    done by the persistent_insert_rules method extended to allow creation
    of the target policy along with the rule inserts.

    Database transactions added in persistent_insert_rules to make sure
    all changes (policy add and rules insert) can be committed or rolled
    back together.

    DB table locking expanded to the `policies` table in the policy
    creation case to prevent conflicting policy changes from other nodes.

    policy_model add_item API method extended to accept policy item with
    rules, (exclusive) or parameter specifying ID of library policy to
    activate.

    Partially implements: blueprint policy-library
    Partial-Bug: 1693622

    Change-Id: I2a83ac11b7014d417ff7553f602a8bb96a9adc34

[Eric K (ekcs)]

APIs are in. CLI remain.