* Fix: 'slug' requirement in API Update function removed, as it could cause pre version 2.0 clients to have failed update request.
* Fix: Software Title on Product edit > API tab can no longer be updated, as it was deprecated at version 2.0.
* Fix: Incorrect product_id was found if the client sent a legacy Software Title string, rather than the new numeric value for the product_id to the API Update function. This caused legacy API Update requests to fail, particularly for Variable products.
* New: Added Requires PHP version data option to the WordPress plugin information API.
* New: Requires PHP version field added on the Product edit API tab, and Variable product variation settings.
* New: Added icons to product API tab.
* New: Added My Account dashboard API Keys and API Downloads tab icon when using Storefront theme.
* New: Added 'wc_api_manager_update_active_required_keys' filter to API Update function.
* Tweak: Optimize get_secure_order_download_url() method.
* Tweak: Move WooCommerce version requirement notice before WooCommerce_API_Manager class to be certain the API Manager does not load until after the WooCommerce minimum version requirement has been met.
* Tweak: Replace get_all_orders() method with get_all_order_ids() method.
* Tweak: Use wc_get_orders() for get_all_order_ids() method to insure compatibility when WooCommerce moves orders to a custom database table.
* Tweak: Free memory as wc_am_update_201_data_migrate_access_granted_to_order_created_time() loops through orders to make it more memory efficient.
* Tweak: Change api-keys.php template column wording from Product by Product ID to Product Title.
* Tweak: Change api-keys.php template column Product ID cell data from URL to plain text to make it easier to copy.
* Tweak: Template overrides for yourtheme/woocommerce/api-keys.php, and yourtheme/woocommerce/api-downloads.php have moved to yourtheme/woocommerce/myaccount/api-keys.php, and yourtheme/woocommerce/myaccount/api-downloads.php
* Fix: The API Manager no longer relies on the woocommerce_downloadable_product_permissions table for download data, but rather only looks for the first Downloadable files URL on the product due to issues described in the following docs. Please read Digital/Downloadable Product Handling - WooCommerce Docs for more information on how adding/changing Downloadable files URLs on products can cause download/update URLs to stop working since WooCommerce 3.0.
* Tweak: Added Product ID to api-keys-order-complete.php email template.
* Tweak: Added Product ID to api-keys.php template.