Allow enabling sand duping (#10191)

Because this exploit has been widely known for years and has not been fixed by Mojang, we decided that it was worth allowing people to toggle it on/off due to how easy it is to make it configurable.

It should be noted that this decision does not promise all future exploits will be configurable.

patches/server/0777-Fix-plugin-loggers-on-server-shutdown.patch

@@ -0,0 +1,67 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Jos=C3=A9=20Miguel=20Moreno?= <josemmo@pm.me>
+Date: Sat, 5 Jun 2021 13:45:15 +0200
+Subject: [PATCH] Fix plugin loggers on server shutdown
+
+
+diff --git a/src/main/java/io/papermc/paper/log/CustomLogManager.java b/src/main/java/io/papermc/paper/log/CustomLogManager.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..c1d3bac79bb8b4796c013ff4472f75dcd79602dc
+--- /dev/null
++++ b/src/main/java/io/papermc/paper/log/CustomLogManager.java
+@@ -0,0 +1,26 @@
++package io.papermc.paper.log;
++
++import java.util.logging.LogManager;
++
++public class CustomLogManager extends LogManager {
++    private static CustomLogManager instance;
++
++    public CustomLogManager() {
++        instance = this;
++    }
++
++    @Override
++    public void reset() {
++        // Ignore calls to this method
++    }
++
++    private void superReset() {
++        super.reset();
++    }
++
++    public static void forceReset() {
++        if (instance != null) {
++            instance.superReset();
++        }
++    }
++}
+diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
+index ab1f4e62b2ffed99b47ae23cae172f20ed586b27..97dbe5a44d2791c6dee830654c3935f4ac54aad4 100644
+--- a/src/main/java/net/minecraft/server/MinecraftServer.java
++++ b/src/main/java/net/minecraft/server/MinecraftServer.java
+@@ -1223,6 +1223,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+                 } catch (Exception ignored) {
+                 }
+                 // CraftBukkit end
++                io.papermc.paper.log.CustomLogManager.forceReset(); // Paper - Reset loggers after shutdown
+                 this.onServerExit();
+             }
+ 
+diff --git a/src/main/java/org/bukkit/craftbukkit/Main.java b/src/main/java/org/bukkit/craftbukkit/Main.java
+index db6398c1822f6ad499feddd6a915984ef9917777..d931a4c6e633bf9c1b3e5e18e880e2ddbfe4aa2a 100644
+--- a/src/main/java/org/bukkit/craftbukkit/Main.java
++++ b/src/main/java/org/bukkit/craftbukkit/Main.java
+@@ -18,6 +18,12 @@ public class Main {
+     public static boolean useJline = true;
+     public static boolean useConsole = true;
+ 
++    // Paper start - Reset loggers after shutdown
++    static {
++        System.setProperty("java.util.logging.manager", "io.papermc.paper.log.CustomLogManager");
++    }
++    // Paper end - Reset loggers after shutdown
++
+     public static void main(String[] args) {
+         // Paper start
+         final String warnWhenLegacyFormattingDetected = String.join(".", "net", "kyori", "adventure", "text", "warnWhenLegacyFormattingDetected");