Nova instance config drive Metadata Definition

A nova Juno FFE landed to support setting the
img_config_drive property on images to require images
to be booted with a config drive. The Glance Metadata
Definitions should include this property.

See Nova Blueprint:
https://blueprints.launchpad.net/nova/+spec/config-drive-image-property

Change-Id: Iffc4d4f00f3677ed1fa41233ef6cfbc5c46d8602
Closes-bug: 1367981
Add missing metadefs for Aggregate Filters

The below spec implemented in Juno added numerous properties
that can be added to Host Aggregates. The Metadata
Definitions catalog should include them.

https://github.com/openstack/nova-specs/blob/master/specs/juno/per-aggregate-filters.rst

Change-Id: Id37028b4b24ab5f6b0c4547a3c1af47bd76e61f6
Closes-bug: 1368032
Specify the MetadefNamespace.namespace column is not nullable

The metadef_namespaces table definition indicates the namespace
column as not accepting nulls. The related MetadefNamespace ORM class
should also indicate that the namespace column does not accept nulls
with "nullable=False" in the column definition.

Change-Id: I681747b6579a2284f23bf154889a61c639b0616d
Closes-Bug: 1367619
hacking: upgrade to 0.9.x serie

Change-Id: I252758fd633662de9659a402c5e3d7e3ce1fae0f
Merge "Specify the MetadefNamespace.namespace column is not nullable"
Merge "Nova instance config drive Metadata Definition"
Merge "Add missing metadefs for Aggregate Filters"
Merge "hacking: upgrade to 0.9.x serie"