YITH WooCommerce Wishlist Premium 3.31.0

* New: WooCommerce 3.4 compatibility
* New: WordPress 4.9.6 compatibility
* New: updated plugin framework
* New: GDPR compliance
* New: register dateadded field for the lists
* Tweak: replaced create_function with a proper class method, to improve compatibility with PHP 7.2 and avoid warnings
* Fix: js error when switching from Premium version to Free
* Fix: preventing add_rewrite_rule when WPML is active, to avoid possible Internal Server Error (thanks to Adri & Bruno)
* Fix: icon replacement not working on variable Add to Cart
* Fix: preventing warning "Illegal string offset" when get_availability() returns empty string instead of array
* Update: Italian language
* Dev: added filter yith_wcwl_redirect_url
* Dev: added filter yith_wcwl_login_notice

New: tested with WooCommerce 3.3.0
Fix: issue with Add to Wishlist shortcode when global $product not defined

• New: WooCommerce 3.2.6 compatibility
• New: plugin-fw 3.0
• New: added js compatibility to Infinite Scrolling
• New: added "Last promotional email sent on" info, for admins
• New: added option to export users that added a specific product to their wishlists, using csv format
• New: added Swedish - SWEDEN translation (thanks to Suzanne)
• New: added Dutch - NETHERLANDS translation
• Tweak: improved wishlist-view template checks and params
• Tweak: wishlist now registers (and shows) "date added" param for unauthenticated users too
• Tweak: added check over product object, to avoid Fatal when printing Add to Wishlist shortcode
• Fix: fixed security vulnerability, causing possible SQL Injections (huge thanks to John C. and Sucuri Vulnerability Research team)
• Dev: added filter yith_wcwl_estimate_additional_data to let developers add custom data to print in Estimate Email template
• Dev: added yith_wcwl_removing_from_wishlist / yith_wcwl_removed_from_wishlist hooks
• Dev: added params to main triggers in wishlist js code