Merge changes from topic 'clustering-stable/boron' into stable/boron

* changes:
  Bug 6396: Integrate faas renderer with clustering singleton service
  Bug 6396: Integrate neutron-ovsdb with clustering singleton service
  Bug 6396: Integrate neutron mapper with clustering singleton service
  Bug 6396: Integrate iovisor renderer with clustering singleton service
  Bug 6396: Integrate openflow-overlay with clustering singleton service
  Bug 6396: Integrate l2-l3-domain-extension with clustering singleton service
  Bug 6396: Integrate ne-location-provider with clustering singleton service
  Bug 6396: Integrate vpp-renderer with clustering singleton service
  Bug 6396: Integrate neutron-vpp-mapper with clustering singleton service