Fix - Missing CSS and JS assets causing broken styles and functionality.
* Tweak - Refactor address validation
* Fix - Fatal error with custom billing fields added from 'woocommerce_checkout_fields' filter hook.
* Tweak - Use order CRUD classes to save or get meta data.
* Fix - Editing address in admin does not support custom address fields.
* Tweak - Remove the empty recipient-form.php file.
* Fix - Different subtotal, tax, and discount value when one cart item has multiple addresses.
* Fix - Incorrect shipping method in the order.
* Fix - Overlap select field in address form.
* Fix - Different subtotal value when discount coupon is used.
* Fix - "Undefined Index: price" notice error when using WC Composite Product plugin.
* Fix - Address array is missing in package destination.
* Fix - "Set Multiple Address" button to always show regardless of cart item quantity.
* Fix - Shipping methods always display "(incl. tax)" text regardless of tax display settings.
* Add - Save billing address fields functionality when click "Set Multiple Address" button.
* Tweak - Move the location of the "Set Multiple Address" button to shipping address area.
* Tweak - Simplify duplicate cart process.
* Fix - Taxes added even when customer is tax exempt.
* Tweak - Refactor the code for add ons compatibility.
* Fix - Use subtotal for free shipping calculation.
* Fix - Add new address button does not work in plain or numeric permalink.
* Fix - Display multiple addresses in preview order.