Minecraft wiki entry for Development_versions, associated text: Now generate grass under stairs instead of a dirt path.
Villages in savanna and taiga biomes now use the appropriate type of wooden fences.
Cobblestone now generates around wells instead of gravel.
Paths now only replace grass blocks with air above water, lava, sand, sandstone, and red sandstone. All other blocks will be ignored, with blocks below (down to sea level) considered for replacement instead.
This allows paths to generate properly under trees.
This removes the ability for paths to bridge ravines.
Zombie villagers generated in zombie villages no longer despawn (i.e. they have the PersistenceRequired flag set).