Add support for multi-region (AVAILABLE_REGIONS)

[Mathieu Gagné]

Horizon allows you to support multi-region with the AVAILABLE_REGIONS configuration.

We should support this configuration.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/73675

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/73675
Committed: https://git.openstack.org/cgit/stackforge/puppet-horizon/commit/?id=a4e617ff1bba9b5025d48888fd379425644e7751
Submitter: Jenkins
Branch: master

commit a4e617ff1bba9b5025d48888fd379425644e7751
Author: Mathieu Gagné <email address hidden>
Date: Fri Feb 14 12:37:46 2014 -0500

    Add ability to configure AVAILABLE_REGIONS

    Example on how to use this setting:

      class { 'horizon':
        available_regions => [
          ['http://region-1.example.com:5000/v2.0', 'Region-1'],
          ['http://region-2.example.com:5000/v2.0', 'Region-2']
        ]
      }

    Change-Id: I75a123d1fda3861d467dd6b05f1e621b41d8c30b
    Closes-bug: #1280365