WooCommerce Follow Ups Emails 4.9.51

* Fix: Issue where interval and duration parameters are not respected when creating an email via REST API.
* Fix: Broken layout for /unsubscribe, /email-subscriptions, and /email-preferences pages on Twenty Seventeen theme.
* Tweak: Sent emails now contain plain data, besides HTML. This can be disabled by returning false on the filter `fue_multipart_mail`.
* Fix: Abandoned Cart Emails are removed from the queue.
* Fix: PHP notice when testing storewide email.
* Tweak: Extend subscribers with first name and last name.
* Fix: Improve Memberships compatibility.
* Fix: Manual email sending not considering variation products.
* Fix: Use ISO_8601date format to avoid issues with unsupported date formats on WordPres
* Tweak: Clarify the use of `{item_url}` in the tool tip.
* Fix: Allow clear the selected product in trigger setting.
* Fix: Issue where `{item_quantity}` is not replaced correctly when the product in trigger is a variation.
* Fix: Only allow Emails with a type set to be saved.
* Tweak: Follow-Up Email status is active by default.
* Fix: Issue where `{cart_totals}` email variable is not being set properly.
* Fix: Issue where clicking on View Email generates coupons.

* Fix: PHP notice caused by product properties accessed directly.
* Fix: Issue where "After Booking is Created" trigger is not sending email when a booking is purchased.
* Fix: Use email from customer for booking created manually without order associated.
* Fix: Issue where bookings emails with **Remove on status change** enabled are not removed from the queue when order is cancelled.
* Fix: Issue where no emails get scheduled when adding an additional trigger based on shipping method.
* Fix: Rename {course_results} to {course_results_url} and set the replacement with course results page URL.
* Fix: If the available meta is course_id (e.g. the trigger is "after course is completed"), set {quiz_mark} from course pass grade and {quiz_grade} with user total grade for the course.
* Fix: Refresh coupon variables in vars meta box when email vars section is updated.
* Fix: Issue where event tickets plugin breaks loading of email variables meta box.
* Fix: Issue where Event Tickets emails are not triggered when specific event category is set.
* Fix: Issue in impporting orders that might be stopped because of error reading the order information.
* Fix: Issue where multiple abandoned cart emails are not scheduled after adding products to the cart.
* Fix: WooCommerce 3.0+ "accessing properties directly" notice when using coupon.
* Tweak: Don't proceed test email if email field is empty.
* Tweak: Add {order_pay_url} variable that will render URL for customer to pay their (unpaid - pending) order.
* Tweak: Add preempt filter for WC order email scheduling to allow short-circuit email insertion's return value.
* Tweak: Add option for forcing twitter handle as a requirement in Twitter Follow-Ups. Default to 'no', but if set to 'yes' tweet only happens if customer has twitter handle.

* Fix: Issue where {amount_spent_order} variable in Customer Email is passed as zero.
* Fix: Issue where list attribute in [fue_subscribe] is not working properly.
* Fix: Warning notice (illegal string offset) when store-wide follow-up email is sent after the purchase of a variable product.
* Fix: Tweets do not work.