WooCommerce Product Add-Ons 6.8.2

* Fix - When re-ordering, not all addons accounted for.
* Fix - Do not show addon totals before variations have been selected.
* Fix - When removing old global addons after import, all addons disappears.
* Fix - Taxes not calculating correct on display when using {price_including_tax} in price suffix.
* Update - Changed default Grand Total verbiage to Sub total for a more accurate description.
* Update - WC tested up to version.

* Fix - Further updates for WooCommerce 3.0 compatibility.
* Fix - Minor code cleanup (unused variable, PHPDocs).
* Fix - Variable products with required custom textarea not able to add to cart.
* Fix - Prevent global addon fields not saving when no name is entered.
* Fix - Issue resetting global product.
* Fix - Don't make custom price input required when not set.
* Add - new REST API endpoints for managing global and product addons
* Fix - Fatal error when combined with the Memberships extension.
* Fix - When grouped product contains simple and subscription product amount suffix shown incorrectly.
* Fix - Re-order addons were not being added.
* Fix - Notices when product object not found.
* Fix - Prevent filtering prices twice due to context issue.
* Fix - Inline VAT/TAX pricing not updating correctly on product page on addon grand total.
* New - Added the new Woo plugin header, for WooCommerce 3.1 compatibility.
* New - Compatibility with Smart Coupons Credit/gift coupon.

* Fix - Update for WooCommerce 3.0 compatibility.