New Chef cookbooks for client services, Sahara and Trove.

Added "cookbook-openstack-data-processing" for supporting the Sahara project.

Added "cookbook-openstack-database" for supporting the Trove project. There was
an active discussion and voting around naming the repository, but since other
OpenStack services do not include -service in their name, "openstack-database"
was chosen. We should be able to keep this straight from the "database" and the
"openstack-ops-database" cookbooks

Added "cookbook-openstack-client" to serve the need for a cookbook containing
Resources for interacting with OpenStack services (Cinder, Heat, Swift, etc.).
Will mostly contain LWRPs for interacting via recipes and with Chef Metal.

Change-Id: Ifffe3c24617092a530f5e31741e24cff3154e04a
Merge "New Chef cookbooks for client services, Sahara and Trove."