Add scope_types for user policies
Add scope_types for user policies

This commit adds the scope types for all user policies. This is the
first step towards making keystone APIs more flexible for project or
domain administrators. It should also result in more security because
enforcing scope will ensure proper scoped-RBAC enforcement.

Change-Id: I5ddde56e8dcc85b7c98af3207af0e81fd64b2514

mahak/keystone,mahak/keystone,openstack/keystone,openstack/keystone,mahak/keystone,openstack/keystone