Add attributes for swift_enable_snet & swift_store_region

- Add default["openstack"]["image"]["api"]["swift"]["enable_snet"] attribute
- Add default["openstack"]["image"]["api"]["swift"]["store_region"] attribute
- Set defaults such that the end result doesn't change, but attributes
  can be overridden.
- Add tests for these 2 attributes
- Add README.md entries for these 2 attributes

Change-Id: I8dd10a9731f996ebe6b064d2552f9cc5a1bf468d
Closes-Bug: #1274937
Merge "Add attributes for swift_enable_snet & swift_store_region"
Add client recipe for image

Add an explicit recipe for installing client
only packages.
Tests are also included.
Bumped minor version for this new feature.

Change-Id: I12808f895757e99d2d60bdb0e8fd85dcd3f8f026
Addresses: blueprint add-client-recipes
Add attribute for image api workers setting

- Add an attribute for ['openstack']['image']['api']['workers']
- Adjust the template for glance-api.conf to use this attributes
- Adjust the default value to be a maximum of 8 (but this can be
  overridden)
- Adjust spec tests to set the cpu value so they converge
- Add test to confirm this value can be set
- Add test to confirm the .min[8 , sets a max of 8.
- Add README.md attribute entry

Change-Id: I8bdbd8bc8fe9af7a9ca3bbc8856d5a200ce7be7b
Closes-Bug: #1274884
Add rabbit/qpid notification_topic attribute to template

- Utilise the rabbit/qpid notification_topic attributes from
  openstack-common in the glance-api.conf.erb template.
- Write tests to confirm these attributes are set.

Change-Id: Ia939d25dae0d0ee5bbe53777893807ed8b61d579
Closes-Bug: #1274879