Java Edition Alpha v1.0.3

Alpha v1.0.3 is a version released to add new sounds and to change the behavior of mobs.

Additions

 * Hostile mob sounds.
 * Prior to this update, they shared the player's hurt sound.
 * Ambient cave sounds.

Changes

 * Mob pathfinding has been improved on hills, except for spiders.
 * Generally more convincing mob idling behavior. They stand still more often, looking around at their surroundings.