get_order wrapper function for new factory
Replace new WC_Order calls with get_order
Using &ndash; for compatibility
Created WC_Abstract_Order, extended by WC_Order
Restore get_order call in WC_Order constructor
Calculate tax and totals methods
Tax class fixes + notices
Cleaned up ajax tax calc function
Notices
fixed undefined variable $status, closes #5673
Merge pull request #5674 from claudiosmweb/5673-fix-template-file-check-broken

Fix undefined variable $status in WC_Admin_Notices::template_file_check_notice()
Merge pull request #5672 from SiR-DanieL/patch-2

Wrong non ASCII content
WC_Order is default class for order factory
Added comment to indicate that WC_Order shouldn't be directly instantiated
add filter to is_purchasable()
Update template file to exit if accessed directly

Noticed this missing, wasn't sure if it was intentional but thought it
best be added.
[2.1] Total tax should be +, not -
changed the address format in plain text emails
moved the wc_ship_to_billing_address_only() function to wc-order-functions.php
adding brackets around if statement