Java Edition 1.9.1-pre1

1.9.1-pre1 is the first pre-release for 1.9.1.

Additions

 * Added elytra sound effects.
 * Sound event
 * Armor attribute
 * Damage formula is now, i.e. increased toughness means less armor defense point reduction from strong attacks.
 * Diamond armor has toughness 2, all other armor has toughness 0. A full set of diamond armor therefore gives a toughness attribute of 8.
 * New option  in options.txt
 * Defaults to false. When false, the client will ignore attempts to attack when weapon cooldown is less than 75% recharged. (The effect was removed in the final release, however the option itself remains.)

Changes

 * Session ID is now no longer printed by the game to the log files or to the launcher.
 * Entity selector  (count) now sorts on proximity using true coordinates, not coordinates snapped to the grid.
 * Missing an attack no longer triggers the weapon cooldown (later reverted in final release.)
 * Loot tables now also work in dispensers and droppers
 * Dispensers with arrows in jungle temples now use loot tables.
 * Hoppers can now push and pull items to and from blocked chests.
 * Increased limit per tick for scheduled tile ticks from 1,000 to 65,536.
 * Improved AI.

Fixes

 * Other fixes:
 * Fixed game engine adding non-existent entities (failed mob spawns, etc.) to its internal lists, increasing instability.