Advanced Custom Fields Pro 6.4.0.1

* Fix - Fixed vulnerability allowing author role to save unfiltered HTML values.
* Fix - Fixed all metaboxes appearing when editing a post in WP 5.0.
* i18n - Updated Polish translation thanks to Dariusz Zielonka.
* i18n - Updated Czech translation thanks to Veronika Hanzlíková.
* i18n - Update Turkish translation thanks to Emre Erkan.
* i18n - Updated Portuguese language thanks to Pedro Mendonça.

• Fix - Fixed various plugin update issues.
• Tweak - Added 'language' to Google Maps API url.
• Dev - Major improvements to the acf.models.Postbox model.
• Dev - Added JS filter 'check_screen_args'.
• Dev - Added JS action 'check_screen_complete'.
• Dev - Added action 'acf/options_page/submitbox_before_major_actions'.
• Dev - Added action 'acf/options_page/submitbox_major_actions'.
• i18n - Updated Portuguese language thanks to Pedro Mendonça

* Fix - Fixed unload prompt not working.
* Dev - Reduced number of queries needed to populate the relationship field taxonomy filter.
* Dev - Added 'nav_menu_item_id' and 'nav_menu_item_depth' to get_field_groups() query.
* Dev - Reordered various actions and filters for more usefulness.
* i18n - Updated Polish language thanks to Dariusz Zielonka