dashboard queries should support selected region

[Eric Peterson]

When running / writing queries - there are times where you might want to use the currently selected region (in horizon) as a query parameter. So maybe there is a chart that allows you to see "regionA" when you select "regionA", and when you change your region in horizon the monasca chart would reflect your new region.

[Eric Peterson (ericpeterson-l)]

In order to read this info, the horizon plugin should access request.user.services_region to find what the currently selected region is.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/231071

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/234260

[OpenStack Infra (hudson-openstack)]

Change abandoned by Bradley Klein (<email address hidden>) on branch: master
Review: https://review.openstack.org/231071
Reason: replacing this patch with https://review.openstack.org/#/c/234260/ -- rebase not making this patch happy

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/234260
Committed: https://git.openstack.org/cgit/stackforge/monasca-ui/commit/?id=2b62daa655bd026299efa913bfc42c32c086aec8
Submitter: Jenkins
Branch: master

commit 2b62daa655bd026299efa913bfc42c32c086aec8
Author: bklei <email address hidden>
Date: Tue Oct 13 08:41:02 2015 -0600

    Scope requests to horizon scoped region

    Instead of adding region to all requests by default if not
    specified, we'll instead honor a region of 'INJECT_REGION'.
    This is because not all environments add region as a dimension
    for metrics, so we can't do this by default.

    Change-Id: I126cd604b3b6d84d0f4efa5dc99aa538e6cf0d77
    Closes-Bug: #1494337