- Delay number creation until status is no longer auto-draft. This was broken in 1.4.0 when compat with WC 3.0 was added.

V1.4.2: Allow checking for empty list in variable definitions by simply leaving comparison field blank

Fixes #18

Fixes #15

Add variable issuborder to let admins use different order number formats for suborders created by YITH multivendor

Fixes #16

V1.3.9: Fix issues with the WC PDF Invoices & Package Slips plugin (numbers were created even if disabled and even before invoices were actually created)

V1.3.8: Add debug messages to the update system (disabled by default); Remove debug code that causes problems in strict mode

V1.3.7debug1: Debug version for Blaine Rittmer: Downloading the update information works, converting to JSON seems to fail, so we need to add debug statements in that area...

  * [Shipping] (shipping costs)
  * [ShippingMethods] (user-readable string)
  * [ShippingMethodIDs] (internal, unique IDs for shiping methods, like shipping_by_rules:31)
  * [ShippingMethodTypes] (shipping plugin names)
  * [ShippingInstanceIDs] (unique identifiers for shipping instance when using zones)

Fixes #13

Fixes #14.

V1.3.6: Fix order numbers for old orders; Fix JS for update credentials to include the slug and thus work when two OpenTools plugins are installed

V1.3.5: Added variables [MonthName], [MonthName3], [Week], [WeekNumberYear], [DayOfYear], [Weekday], [WeekdayName], [WeekdayName3] (advanced version only)

- Order tracking assumed the user entered the order ID => implement filter to convert the entered order number into the corresponding ID
- Added trigger woocommerce_order_id_from_number(ordernumber) that returns the order ID if found (if not found, returns ordernumber unchanged)

V1.3.1: Support for generic invoice number API (http://www.open-tools.net/blog/63-proposal-for-a-general-api-for-third-party-woocommerce-invoice-numbering-plugins.html); Implementation for five different invoicing plugins

Support for almost all third-party invoice plugins (patches ready to be submitted to the respective authors, this plugin needs hardly any change)

-) Add filters to query whether a third-party plugin claims responsibility for invoice numbers
-) Add filter to get the configuration link for this plugin
-) Move all configuration / documentation links to a class-wide property to avoide duplication
-) Generic function to check whether order/invoice numbers are enabled