Minecraft wiki entry for Development_versions, associated text: Renamed BlockTypes class to MinecraftBlockTypes
Renamed Effects class to MinecraftEffectTypes
Renamed Items class to MinecraftItemTypes
Events
Added read-only property currentTick to tick event - Returns the current server tick
Renamed event createEntity to entityCreate
Renamed event addEffect to effectAdd
Renamed event activatePiston to pistonActivate
Renamed event beforeActivatePiston to beforePistonActivate
Renamed event explodeBlock to blockExplode
Renamed event changeWeather to weatherChange