Updated Upstream (Bukkit/CraftBukkit)

Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

Bukkit Changes:
39ce5d3a SPIGOT-4399: ItemMeta.equals broken with AttributeModifiers

CraftBukkit Changes:
1cf8b5dc SPIGOT-4400: Populators running on existing chunks
116cb9a1 SPIGOT-4399: Add attribute modifier equality test
5ee1c18a SPIGOT-4398: Set ASM7_EXPERIMENTAL flag

Spigot-Server-Patches/0282-Implement-World.getEntity-UUID-API.patch

@@ -0,0 +1,28 @@
+From 6fb6eaa3ed3eec1ca82a483f94c033416632b0c4 Mon Sep 17 00:00:00 2001
+From: Brokkonaut <hannos17@gmx.de>
+Date: Tue, 3 Jul 2018 16:08:14 +0200
+Subject: [PATCH] Implement World.getEntity(UUID) API
+
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+index da141748bd..b37864e2b8 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
++++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+@@ -751,6 +751,14 @@ public class CraftWorld implements World {
+         return list;
+     }
+ 
++    // Paper start - getEntity by UUID API
++    public Entity getEntity(UUID uuid) {
++        Validate.notNull(uuid, "UUID cannot be null");
++        net.minecraft.server.Entity entity = world.getEntity(uuid);
++        return entity == null ? null : entity.getBukkitEntity();
++    }
++    // Paper end
++
+     public void save() {
+     // Spigot start
+         save(true);
+-- 
+2.19.0
+