pass $children variable (variations) to the woocommerce_variable_product_sync hook
Changed label of orderby setting in product category widget.
polish up attributes section confusing tips.
Take out default variations #3169
Only load integration abstract when needed #3169
Fix up markup on form-add-payment-method.php

So that checkout.js correctly displays payment method's fields.
Part of #3396
Only display add_payment_method() when logged in

Part of #3396
Improve form-add-payment-method.php error & button

Part of #3396
Call add_payment_method_action()

Part of #3396
Redirect to My Account page after adding method

Part of #3396
Add a notice that payment method has been added

Part of #3396
Filter gateways for add_payment_method form

Part of #3396
Fix "non-static method called statically" notice