Rajaram/Vinkesh|Default xmlns for extension serialization can be overriden, added default factory for extension middleware
Rajaram/Vinkesh|Default xmlns for extension serialization can be overriden, added default factory for extension middleware

citrix-openstack-build/pbr,citrix-openstack-build/pbr,openstack-dev/pbr,JioCloud/pbr,openstack-dev/pbr,varunarya10/pbr,klmitch/pbr,redhat-openstack/pbr,varunarya10/pbr,WiFast/pbr,emonty/oslo-packaging,JioCloud/pbr,citrix-openstack-build/pbr,openstack-dev/pbr,WiFast/pbr,redhat-openstack/pbr,klmitch/pbr,emonty/oslo-packaging