improvement: add option to import default attributes via xpath
bug fix: email sent when order status changed to completed
bug fix: re-running an import with 'Skip posts if their data in your file has not changed' removes product variations in some cases
bug fix: enabling 'Link all variations' and 'Delete posts no longer present in your file' results in variations being deleted
bug fix: unable to add parent SKU when importing products as child element in XML
bug fix: post author for first product variation not imported properly
bug fix: product attributes for first product variation not imported properly
bug fix: changing parent sku creates duplicate variations
bug fix: order line items are imported even if the quantity is 0
bug fix: WooCommerce lookup table not cleaned up when products deleted via cron
bug fix: linked product matching attempted during the import process before all products are imported
bug fix: featured image not updated when only 'Images' is set to be updated in 'Choose which data to update'
bug fix: selective hashing missing for WooCommerce order imports
bug fix: all product attributes updated when choosing only to update specific attributes for child XML variations
bug fix: attributes containing '#' character not imported properly
bug fix: 'Tax amount per unit' field disappears in order import options
bug fix: 'Enable reviews' option not migrated
bug fix: product_shipping_class taxonomy not updated
bug fix: advanced options are not pre-selected in the 3rd (and all subsequent) attributes in 'Attributes' tab
bug fix: order author is updated when only updating order status
