Minecraft wiki entry for Development_versions, associated text: Changed the spawning logic for iron golems and cats to make it easier for them to spawn in roofed areas, like underground villages. (MCPE-142292)
Scaffolding can no longer be placed without support on Y=0. (MCPE-150765)
Fire that exists before the doFireTick game rule is enabled will continue to spread again. (MCPE-140396)