Minecraft wiki entry for Development_versions, associated text: MC-151047 – Trader llamas immediately disappear when spawned with a spawn egg.
MC-151062 – Grindstoning an enchanted book without a custom name names the new (unenchanted) book "Enchanted Book".
MC-151213 – Observers don't trigger twice when chained and moved
MC-151329 – Major FPS drop after running a mob farm for 30 minutes.
MC-151365 – Flaming arrows can light waterlogged campfires.
MC-151418 – Observers don't update redstone properly.
MC-151674 – RegionFiles are not closed when they are evicted from cache.