Minecraft wiki entry for Development_versions, associated text: Added new overload for /replaceitem with an option for destroy (the old behavior) or keep (the command will return an error if an item occupies that slot).
Fixed a bug where a mob wouldn't delete its goal if all goals were trying to be removed.
Fixed spamming of particles, sounds, and events for looped, non-zero-length animations with timelines.
Fixed a syntax error issue when running the /xp command with levels.
Fixed an issue with “A Nightmare in Candyland” map which was no longer teleporting players correctly.