proper migration to gamerules for keep spawn loaded distance

patches/server/0211-Implement-World.getEntity-UUID-API.patch

@@ -0,0 +1,26 @@
+From 0000000000000000000000000000000000000000 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 f2e67748d2970207907b3120b0d0fb50744eb7c2..2abd68c5a8c53dfc503b732f64b3ba3195244fbf 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
++++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+@@ -1100,6 +1100,15 @@ public class CraftWorld extends CraftRegionAccessor implements World {
+         return list;
+     }
+ 
++    // Paper start - getEntity by UUID API
++    @Override
++    public Entity getEntity(UUID uuid) {
++        Preconditions.checkArgument(uuid != null, "UUID cannot be null");
++        net.minecraft.world.entity.Entity entity = world.getEntity(uuid);
++        return entity == null ? null : entity.getBukkitEntity();
++    }
++    // Paper end
++
+     @Override
+     public void save() {
+         org.spigotmc.AsyncCatcher.catchOp("world save"); // Spigot