* Move Cron tasks to Action Scheduler
* Make sure temporary PDFs and Zip files are deleted hourly.
* Filter for "$next_invoice"
* PDF invoice email for resending the invoice to a customer from order list or individual order
* Allow individual invoices to be deleted or created (requires debugging to be on and admin only)
* MOAR filters!
* Change the way the next invoice number is checked for.
* Begin cleaning up some methods.
* WooCommerce 3.8
* Fix [[PDFORDERDISCOUNT]] not displaying coupons and discount
