* Fix - Ensure calculated inventory reduction is correct when using IPN gateways in WooCommerce 3.0+
* Fix - "Sold Individually" setting respected when "Calculated Inventory" is enabled in WooCommerce 3.0+
* Fix - Incorrect unit prices for simple products or variations displayed when using quantity-based pricing in WooCommerce 3.0+
* Fix - Incorrect line item price when using unit price and a remaining stock of "1" in WooCommerce 3.0+
* Fix - Ensure variations fallback to parent product measurements if not set in quantity-based mode