[CNS] update submodule packages/openwrt to support attr and tar extended attributes (#200)
[CNS] use tar --xattrs for data-overlay deployment and confine_sliver_dump_overlay (#200)
[CNS] confine_sliver_deploy: postfix (the ugly way) extended attributes for deleted files and directories. Should be reverted once tar --xattrs works properly (#200)
[VCT] add vct_build_node_base_image_clean function to allow building from scratch