Java Edition 13w21b

13w21b was released to fix some of the bugs and crashes in the 13w21a snapshot.

Fixes
7 bugs fixed
 * – Certain death message will print "null" as the player/mob name that caused the death
 * – Enchanted Items stored in a Donkey / Mule lose enchantments on its death
 * – Sprinting and Speed effect not working
 * – Server doesn't translate strings
 * – No sounds after a while / Music corrupting sound
 * – Crash: IllegalArgumentException
 * – lang files for en_US is grammatically incorrect at death.fell.finish.item