Multiple categories in the product_category shortcode

Add the ability to input multiple categories separated by a comma in the
[product_category] shortcode.
IT languages update
Corrected duplicated settings_page() content

Replaced duplicated call to `array( $this, 'settings_page' )` with `null` to prevent the HTML from being printed to the admin settings twice.
Add woocommerce_product_visibility_options filter

Matches filter used in class-wc-admin-post-types.php
Add an order action to 'create credit note'
Get transaction ID method
Process_refund()

#3164
PayPal implementation of Process_refund()

#3164
Prevent notices in factory
Use get_transaction_id
Rough, non-functioning example of the UI for refund total and add items in the order items panel

#3164
More refund UI  -show qty boxes and totals
More UI / Split up meta box scripts
split up meta box scripts
created initial refund class and function
fixed refund tax
fixed tax default value
Merge pull request #5810 from claudiosmweb/feature-create-order-refund-function

Initial refund class and function
created order_type taxonomy
add refund term in order_type when install