Add multi-region support to the OpenStack plugins

A new configuration parameter 'Region' is supported for the OpenStack
plugins. If defined, the plugins will use it to look up the endpoints in
the Keystone catalog. Note that the 'region' dimension will be added by
the metric and remote collectors.

Change-Id: Idd7da37aa7c4040b406da53166fb32733f5479b9
1 file changed