Add crafting result slot for sheep breeding. Fixes BUKKIT-2926

Sheep now use the crafting system when breeding to determine what color
their baby should be. This triggers an event but the event wants the
crafting inventory to have a result slot which sheep do not have. This
event could be useful for plugins to control the output of sheep breeding
so instead of disabling it we add a result slot so the event fires without
issue.

src/main/java/net/minecraft/server/EntitySheep.java

@@ -32,6 +32,7 @@ public class EntitySheep extends EntityAnimal {
         this.goalSelector.a(8, new PathfinderGoalRandomLookaround(this));
         this.e.setItem(0, new ItemStack(Item.INK_SACK, 1, 0));
         this.e.setItem(1, new ItemStack(Item.INK_SACK, 1, 0));
+        this.e.resultInventory = new InventoryCraftResult(); // CraftBukkit - add result slot for event
     }
 
     protected boolean be() {