Filter List Regions by 'parent_region_id'

List Regions (GET /regions) has an optional query parameter
'parent_region_id', but the API still returns all the regions.

This fix adds support of filtering regions by an optional query
parameter 'parent_region_id'.

Closes-Bug: #1350192

Change-Id: I59f8d852870bd3ad26622bfcd00dfadfdf9d5b42
Remove unnecessary declaration of CONF

Various files had unnecessary references to the keystone config
file. Remove those lines and the import statement.

Change-Id: Ie0f910cf3c647410e3a9b773fc4043622163b9e4
Add a URL field to region table

Allow a URL to be associated with a certain region.

implements bp keystone-to-keystone-federation

Change-Id: Ib61f9c4c9727eb5e81b7c71102133ef000be395d
Remove _BaseFederationExtension

This class is not needed at the moment as there is only one class that
inherits from it.

Change-Id: I3bb8eb2e1ae62753acadd34a539a6ece571e8913
Merge "Filter List Regions by 'parent_region_id'"
Merge "Add a URL field to region table"
Merge "Remove _BaseFederationExtension"
Merge "Remove unnecessary declaration of CONF"
Do not require method attribute on plugins

Removes the condition that an authentication plugin knows the "method"
name that is going to be used to call it. This condition prevents
different mechanisms like "kerberos" and "saml" from using the same
backend plugin.

The client should not know how the server is enforcing the Kerberos
authentication,  mod_auth_kerb or embedded Kerberos,  but the
mod_auth_kerb implementation needs to use the same implementation as an
X509 implementation.

Closes-Bug: #1343709

Change-Id: I6c7d44d3809e5e88cc50c50b6df6f3a154df7ab2
Merge "Do not require method attribute on plugins"