Advanced Custom Fields Pro 6.4.0.1

* Fix - Fixed bug preventing the Google Maps Field address from being customised.
* Fix - Improved logic to request and cache plugin update information.
* Fix - Fixed bug preventing JS initialization when editing widgets in accessibility mode.
* Fix - Added missing $parent argument to term_exists() function when adding a new term via taxonomy field popup.
* Fix - Fixed bug where nested Group Fields did not delete their values.
* Fix - Fixed JS error thrown by localStorage if cookies are not enabled.
* Dev - Bumped minimum WP version requirement to 4.4.
* Dev - Added action 'wp_nav_menu_item_custom_fields' for compatibility with other plugins modifying the menu walker class.
* Dev - Added 'multiple' to the allowed attributes for an email field.
* Dev - Added new ACF_Ajax class for upcoming features.

* Core: Minor fixes and improvements

* Core: Major JavaScript updates
* Core: Improved conditional logic with new types and more supported fields
* Core: Improved localization and internationalization
* Repeater field: Improved logic that remembers collapsed row states
* Repeater field: Added support to collapse multiple rows (hold shift)
* API: Improved lookup to find fields without a reference value
* Language: Added Croatian translation
* Language: Updated Italian translation
* Language: Updated Romanian translation
* Language: Updated German translation
* Language: Updated Arabic translation
* Language: Updated Portuguese translation