WooCommerce Order Delivery 2.6.5

* Tweak - Check the time limit for the `start_date` parameter instead of the current date when calculating the first shipping date.
* Tweak - Check the time limit for the next payment date when calculating the first shipping date of an order renewal.
* Tweak - Tested compatibility with WP 5.1.
* Fix - Hide the 'Time frame' label if not present on the order details page.
* Fix - Unlock the delivery dates beyond the subscription billing interval if the setting `subscriptions_limit_to_billing_interval` is not enabled.
* Dev - Updated default values for the arguments in the `wc_od_get_first_shipping_date` function.
* Dev - Updated `order/delivery-date.php` and `myaccount/edit-delivery.php` templates.

* Tweak - Added 'priority' parameter to the delivery fields in the checkout form.
* Tweak - Stop using the deprecated constant 'WC_TEMPLATE_PATH'.
* Fix - Check if the localization parameters exist before using them in the 'wc-od-checkout.js' script.

* Fix - Fixed 'call to undefined function get_current_screen()' issue.