Update CHANGELOG.md

CHANGELOG.md

@@ -5,6 +5,11 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## Unreleased
+### Changed
+- `PriorityQueue.priorityCallback` now takes two arguments.
+- The default priority sort now accounts for most recently used tiles, screenspace error, and distance to the camera.
+- `TilesRenderer.calculateError` no longer returns a value but is now expected to set `__error` and `__distanceToCamera` on the tile itself.
+
 ### Fixed
 - `TilesRendererBase.preprocessURL` types definition.