Enable the Load Balancer v2 for the Ceilometer(Part One)

[OpenStack Infra]

https://review.openstack.org/274518
Dear bug triager. This bug was created since a commit was marked with DOCIMPACT.
Your project "openstack/ceilometer" is set up so that we directly report the documentation bugs against it. If this needs changing, the docimpact-group option needs to be added for the project. You can ask the OpenStack infra team (#openstack-infra on freenode) for help if you need to.

commit c72cd4fa89ec7e0a3d128c216bae89d09f1a7639
Author: Zi Lian Ji <email address hidden>
Date: Sat Jan 23 00:12:32 2016 -0500

    Enable the Load Balancer v2 for the Ceilometer(Part One)

    In this change set, add the new methods:
    list_pools_v2: Support to list the pools with Load Balancer v2 API.
    list_members_v2: Support to list the members with Load Balancer v2
    API.
    list_health_monitors_v2: Support to list the health monitors with
    Load Balancer v2 API.

    In the Load Balancer v2, the responses of the Pool and Member don't
    contian their status. And the status is included in the response of
    status_tree[1].

    We need to query the status_tree to determine the status of them.

    [1]https://wiki.openstack.org/wiki/Neutron/LBaaS/API_2.0

    Change-Id: Ibc49282fa39fed864ec9a54d1f7fb38d7034aa9d
    Implements: blueprint lbaas-v2-enablement
    DocImpact: a new option is introduced

[Zi Lian Ji (jizilian)]

After checking the doc source code, https://github.com/openstack/openstack-manuals/blob/master/doc/config-reference/source/tables/ceilometer-service_types.rst, the configuration item has been updated.