WooCommerce Measurement Price Calculator 3.23.6

* Fix - Fix issue in WooCommerce 3.0+ where an incorrect calculated quantity was added to the cart for calculated inventory/customer-defined measurement products
* Fix - Ensure products created prior to v3.12 use dropdowns when input options are limited

* Feature - Add a percentage overage or cut estimate when accepting customer-defined measurements
* Feature - Optionally limit customer-defined measurements with minimum value, maximum value, or increment
* Fix - Ensure "remaining stock" checks do not fail when inventory is being calculated, but remaining inventory is less than 1 (requires WooCommerce 3.1+)
* Fix - Always persist user inputs if add-to-cart validation fails

* Fix - Ensure calculated inventory reduction is correct when using IPN gateways in WooCommerce 3.0+
* Fix - "Sold Individually" setting respected when "Calculated Inventory" is enabled in WooCommerce 3.0+
* Fix - Incorrect unit prices for simple products or variations displayed when using quantity-based pricing in WooCommerce 3.0+
* Fix - Incorrect line item price when using unit price and a remaining stock of "1" in WooCommerce 3.0+
* Fix - Ensure variations fallback to parent product measurements if not set in quantity-based mode