Add neutron ml2 plugin info to cloud admin guide

[Robert Kukura]

The ml2 neutron plugin was added in havana and needs to be documented in the OpenStack Cloud Administrator Guide.

The monolithic openvswitch and linuxbridge plugins are being deprecated in havana and removed in icehouse, so the sections on these plugins should warn users of this.

Since the openvswitch and linuxbridge L2 agents are fully supported with the ml2 plugin in havana and going forward, details on these agents needs to be clearly separated from details on the plugins they are used with. We don't want users to think these L2 agents are being deprecated.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/49308

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/49308
Committed: http://github.com/openstack/openstack-manuals/commit/2f5084ce705d9d04072b4d83d170a0dce0cdcc15
Submitter: Jenkins
Branch: master

commit 2f5084ce705d9d04072b4d83d170a0dce0cdcc15
Author: Edgar Magana <email address hidden>
Date: Tue Oct 1 22:44:52 2013 -0700

    Include ML2 plugin documentation

    Add ML2 plugin references and description
    Include VXLAN as provider network
    Add a deprecation note for openvswitch and linuxbridge plugins

    Fix bug #1230283

    Change-Id: I5710f81601fdb04b752737dfa0f36fc7863cca9e