YITH WooCommerce Affiliates Premium 3.5.0

* Fix: added missing plugin-upgrade directory

* New: Switch to Cancelled bulk action for payments
* Tweak: improved uninstall procedure
* Tweak: rel nofollow to anchors with query strings
* Tweak: improved click handling for users that does not have yith_wcaf_click_enabled option registered in db
* Update: .pot file
* Update: Dutch version
* Update: plugin-fw
* Fix problem translation on dashboard-withdraw template
* Fix: affiliates not being auto-enaled after registration
* Fix: minimum withdraw conditions
* Dev: New action 'yith_wcaf_after_set_cookie'
* Dev: filter yith_wcaf_payment_table_column_default
* Dev filter yith_wcaf_payments_table_get_columns
* Dev: Fixed action 'yith_wcaf_after_set_cookie'
* Dev: Added new parameters in do_action 'woocommerce_email_header' and 'woocommerce_email_footer' for new affiliate email

* New: WooCommerce 3.6.0 RC1 support
* New: admin can now disable Click handling
* New: current affiliate shortcode
* New: admin can now regenerate invoice for affiliates
* New: admin can now assign coupons to affiliates
* New: affiliates can receive commissions by coupons
* New: email sent when admin assign a coupon to an affiliate
* Update: internal plugin framework
* Update: Spanish language
* Tweak: improved withdraw handling
* Fix: change Generate Link URL in customer emails
* Fix: default value for new_status and old_status in email class
* Fix: billing country on invoices
* Fix: fixed issue with hidden sections (generate link not removed from affiliate dashboard menu)
* Fix: DB error on backend
* Dev: added new filter yith_wcaf_prepare_items_commissions