* fixed: small typo error * fixed: minor styling error in backend product tab fees settings * fixed: Warning: Undefined variable $index in ../classes/class-wc-add-fees.php on line 920
* added: compatibility support for WooCommerce HPOS * cleanup: remove backwards compatibility prior WooCommerce 3.0
* Security fix: added esc_attr to woocommerce-additional-feesv2614class-wc-add-fees.php line 1050ff
