Pocket Edition v0.16.0 alpha build 4

v0.16.0 alpha build 4 (labelled v0.15.90 alpha build 1 in-game and 0.15.90.7 internally) is the fourth build version released for v0.16.0, also known as the Boss Update.

Mobs

 * Wither
 * : When its health reaches 50%, it spawns 3–4 wither skeletons.
 * : New animation when created and killed.
 * : New sounds.

Items

 * Nether star
 * : Potion of Decay.
 * Splash potion of Decay.
 * : Arrow of Decay.

Blocks

 * Beacon
 * The beam is incorrectly displayed by outside.
 * Can be seen correctly by inside.
 * Cannot be colored as dyed glass doesn't exist.

Changes

 * Tweaked the elder guardian's hitbox.
 * Modified natural spawn rates for mobs to where they should be (wither skeleton).
 * Fixed performance issues (FPS drop).
 * Lots of work on horses.
 * Tweaked some UI spacing issues.
 * Tweaked some issues with arrows.
 * More piston work.
 * Removed the, and  commands, introduced in build 1.
 * Now are only for Education Edition.
 * These commands still can be turned on in files (commands/education.json).
 * Removed NPC spawn egg.
 * : Creepers and untamed ocelots now have idle sounds. These were removed (at least for creepers) in a later unknown update.

Fixes

 * Others
 * Mob steps can be heard again.
 * Players can fill buckets while underwater, even in creative.
 * Fixed it so that potions of harming will kill mobs rather than just making them drop loot.
 * Replaced placeholder with the correct names of items.
 * Guardian & elder guardian attack animations are visible again.
 * Fixed attribute inconsistencies in mobs & fixed multiple attribute loading bugs (some mobs ran too fast, some mobs had incorrect health, some mobs didn't show the correct health in their health bar.
 * Fixed crash after joining a LAN game.
 * Fixed randomly breaking boats.
 * Monster spawner no longer crashes the game when difficulty is set to peaceful.
 * Fixed a crash when a player threw a snowball, egg, or splash potions.
 * Zombie pigmen are no longer hostile towards mobs.
 * No more diving when riding a horse, pig, or donkey.
 * Guardian laser beams change color now.
 * Markers on maps now correctly show direction when riding (animal, minecart, etc.)
 * Gamerule settings now persist in saved games.
 * Fixed issue where some mobs dropped no items.
 * Players again spawn in "safe places" during initial world generation.
 * Players no longer float above beds while sleeping.
 * Fixed crash when server spawns guardians & elder guardians.
 * You can hear the laser sound for guardians & elder guardians again.
 * Fixed items dropping from mobs incorrectly (not dropping for some, dropping for some that shouldn't have drops)
 * Chat window fixed- automatically updates messages when they come in.
 * Two zombie villagers no longer spawn when a single villager is turning into a zombie.
 * Status effects no longer present after a player's death.
 * Nether mobs no longer lose fire resistance.
 * Fixed projectiles so they can be shot in directions, not just at targets.
 * Invisible players can no longer be seen and attacked by mobs.
 * Creepers now make hissing ignition sounds again.
 * Iron golem now has an attack animation again.
 * Lightning strikes have sounds again.
 * Fireballs fixed: Blaze fireballs set blocks on fire & large fireballs are visible again.
 * Fixed assorted crashes when loading/importing older worlds.
 * Projectiles no longer hurt the player when reflected.
 * Iron golems will attack aggressive mobs again to defend villagers and themselves.
 * Fixed rare case of mobs spawning without heads.
 * Fixed slime spawning size issues.
 * Zombie pigmen are again spawning with golden swords.
 * Elder guardians now attack the player.
 * Player no longer gets disconnected from the Realm after suspending & resuming the device/game.
 * Fixed a crash that can occur when a skeleton horse trap is triggered on peaceful.