Replace horizon.conf with an angular one

    Horizon configuration is now fully integrated into the angular
application. The object horizon.conf is still available in the
application in order to keep the compatibility, it is a link to the
angular constant object.

Change-Id: I55e1672a89a78032b24c096258471d0ea9d2489e
Implements: blueprint horizon-angular
Add missing mocked calls to the Volumes tests

There is a quota check for the Create Volume button to see if it
should be enabled. These new calls to tenant_quota_usages were missed
when the volume snapshots tests moved to the main volumes
directory/panel.

Change-Id: If09afd6d69a9a9b14dfb6d802be92b7e24e63c60
Closes-Bug: #1284664
Merge "Replace horizon.conf with an angular one"