Initial commit to add a plugin to collectd for obtaining and storing
Gnocchi status metrics. This plug obtains the two metrics provided
by Gnocchi's REST API for "the number of metrics having measures to be
processed" and "the number of measures to process".
This also addes an associated graph in the General OpenStack System
Performance Dashboard and the Controller specific dashboard.
* no longer requires authentication details in the collectd config
* removing the redis exec plugin
* configurable interval for the python plugin now
Change-Id: Idfc5c719e9b0fbaad5db0632a3e5293bf03d7ab6
39cf6ce92e