Minecraft wiki entry for Development_versions, associated text: Mobs are now able to path over azalea blocks (MCPE-129373)
Mobs are now able to path over dripleaf blocks and properly pathfind on top of them, when not fully tilted
Mobs are now able to path over pointed dripstone blocks and properly pathfind on top of them (MCPE-133270)
Mobs can now move properly on top of solid partial blocks, like bells, brewing stands, and enchanting tables
Mobs can now jump from high enough solid partial blocks to full ones at a higher position
Mobs can now jump over fences if they are standing on an adjacent slab or on another block high enough
Mobs can now move through less than half-block tall top snow even when the ceiling, if any, is as tall as the mobs themselves (MCPE-148355)
Mobs can now move through coral and coral fans, as they do not consider them as solid obstacles anymore (MCPE-128687)
Fixed an issue where players could not access a villager's trades while holding a spawn egg (MCPE-76153)
Fixed an issue where witches spawned during village raids could despawn during the raid (MCPE-149883)
Cod, salmon, pufferfish, tropical fish, and dolphins once again spawn in deep variants of ocean biomes (MCPE-150191)