Glance Metadata Definitions Catalog - Seed

Implements: blueprint metadata-schema-catalog

A common API hosted by the Glance service for vendors, admins,
services, and users to meaningfully define available key / value
pair and tag metadata. The intent is to enable better metadata
collaboration across artifacts, services, and projects for
OpenStack users.

This is about the definition of the available metadata that can
be used on different types of resources (images, artifacts,
volumes, flavors, aggregates, etc). A definition includes the
properties type, its key, it's description, and it's constraints.
This catalogue will not store the values for specific instance
properties.

Change-Id: Ib1c1abf80879fb6dcd5ee30c7d2bc65b0ba720d5
DocImpact
Co-Authored-By: Lakshmi N Sampath <lakshmi.sampath@hp.com>
Co-Authored-By: Wayne Okuma <wayne.okuma@hp.com>
Co-Authored-By: Travis Tripp <travis.tripp@hp.com>
Co-Authored-By: Pawel Koniszewski <pawel.koniszewski@intel.com>
Co-Authored-By: Michal Jastrzebski <michal.jastrzebski@intel.com>
Co-Authored-By: Michal Dulko <michal.dulko@intel.com>
Merge "Glance Metadata Definitions Catalog - Seed"