Update CHANGELOG.md

CHANGELOG.md

@@ -5,12 +5,19 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased]
 ### Added
-- Add option to filter key presses and only show key releases
 ### Changed
 ### Deprecated
 ### Removed
 ### Fixed
-- GUI layout made more robust
+
+## [0.4.3] - 2019-06-10 **EXPERIMENTAL TEST RELEASE**
+- Fixed issue #39
+Almost complete rewrite of mouse polling code  
+Multiple event types (Movement, mouse button events) supported per update ("stroke") of the mouse  
+It is now possible to block a button or movement, but leave unblocked events unblocked  
+Previously, a stroke was either blocked or not - if any one part of the stroke was blocked, it was all blocked  
+- [Monitor script] GUI layout made more robust
+- [Monitor script] Add option to filter key presses and only show key releases
 
 ## [0.4.2] - 2019-06-08
 - Fixed issue #37