Minecraft wiki entry for Development_versions, associated text: Entity hit and collision boxes no longer exist during mob death animations. (MCPE-9999)
Wither skeletons are no longer affected by the Wither effect. (MCPE-46317)
Foxes now sleep and find cover during thunderstorms.
Mobs and entities are no longer slowed when walking one block above ice.
Baby zombies are now able to ride zombie pigmen. (MCPE-20163)
The wither no longer runs away from the player after being spawned.
Fixed the held sword position for vex mobs.
The phantom wing flapping animation is faster now. (MCPE-42935)
Endermen are correctly affected by invisibility effect when applied. (MCPE-44492)
Parrots can now fly over fences and walls.
Drowned on land now attack based on brightness levels rather than the time of day.
Mobs standing on slabs are no longer immune to sunlight damage after reloading the world. (MCPE-32822)
Witches no longer spawn in 1.8 high gaps. (MCPE-45935)
Cured zombie villagers now keep their trade level.
Zombies no longer become stuck on doors when pathfinding.
The parrot dancing animation is the correct speed now. (MCPE-48356)
Jockeys no longer get stuck trying to move to unreachable mounts.