YITH Custom Thank You Page for Woocommerce Premium 3.7.0

* New: Support to WooCommerce 3.7.0 RC1
* Update: Plugin Framework
* Update: Dutch Language file

* New: Support for WordPress 5.2
* New: Removed Support for Woocommerce 2.6
* New: Removed Google+ from Social Sharing Box
* Update: Plugin Framework
* Fix: File codification issue UTF-8
* Fix: Downloadable items link deprecated function
* Dev: added filter yctpw_just_purchased_string to change the social box titles

* New: Support for WooCommerce 3.6.x
* New: added compatibility with Enhanced E-commerce for Woocommerce store by Tavtic (free)
* Update: Plugin Core
* Update: Italian language
* Fix: Fixed shortodes not working in gutemberg due to fatal errors
* Fix: Translation Issue
* Dev: added filter yith_ctpw_block_thank_page_visibility
* Dev: added filter yith_ctpw_thanks_pages_slugs_array