Paper 1.13.1 Update

Updated Upstream (Bukkit/CraftBukkit/Spigot)

Bukkit Changes:
2dcc44dc SPIGOT-4307: Fix hacky API for banners on shields
e0fc6572 SPIGOT-4309: Add "forced" display of particles
efeeab2f Add index to README.md for easier navigation
f502bc6f Update to Minecraft 1.13.1

CraftBukkit Changes:
d0bb0a1d Fix some tests randomly failing
997d378d Fix client stall in specific teleportation scenarios
b3dc2366 SPIGOT-4307: Fix hacky API for banners on shields
2a271162 SPIGOT-4301: Fix more invalid enchants
5d0d83bb SPIGOT-4309: Add "forced" display of particles
a6772578 Add additional tests for CraftBlockData
ce1af0c3 Update to Minecraft 1.13.1

Spigot Changes:
2440e189 Rebuild patches
4ecffced Update to Minecraft 1.13.1

Spigot-Server-Patches/Further-improve-server-tick-loop.patch

@@ -12,7 +12,7 @@ Previous implementation did not calculate TPS correctly.
 Switch to a realistic rolling average and factor in std deviation as an extra reporting variable
 
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index c72bdd29d1..687250c639 100644
+index 8dc922ccd0..e8c3dcc244 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
 @@ -0,0 +0,0 @@ public abstract class MinecraftServer implements IAsyncTaskHandler, IMojangStati
@@ -25,34 +25,36 @@ index c72bdd29d1..687250c639 100644
      public java.util.Queue<Runnable> processQueue = new java.util.concurrent.ConcurrentLinkedQueue<Runnable>();
      public int autosavePeriod;
 @@ -0,0 +0,0 @@ public abstract class MinecraftServer implements IAsyncTaskHandler, IMojangStati
-     public CommandDispatcher vanillaCommandDispatcher;
-     // CraftBukkit end
      // Spigot start
--    public static final int TPS = 20;
--    public static final int TICK_TIME = 1000000000 / TPS;
+     public static final int TPS = 20;
+     public static final int TICK_TIME = 1000000000 / TPS;
 -    private static final int SAMPLE_INTERVAL = 100;
--    public final double[] recentTps = new double[ 3 ];
++    private static final int SAMPLE_INTERVAL = 20; // Paper
+     public final double[] recentTps = new double[ 3 ];
      public final SlackActivityAccountant slackActivityAccountant = new SlackActivityAccountant();
      // Spigot end
- 
 @@ -0,0 +0,0 @@ public abstract class MinecraftServer implements IAsyncTaskHandler, IMojangStati
-         this.isRunning = false;
      }
  
--    // Spigot Start
--    private static double calcTps(double avg, double exp, double tps)
--    {
--        return ( avg * exp ) + ( tps * ( 1 - exp ) );
+     private boolean aT() {
+-        return SystemUtils.b() < this.aa;
++        return System.nanoTime() - lastTick + catchupTime < TICK_TIME; // Paper - improved "are we lagging" check to match our own
+     }
+ 
+     // Spigot Start
+@@ -0,0 +0,0 @@ public abstract class MinecraftServer implements IAsyncTaskHandler, IMojangStati
+     {
+         return ( avg * exp ) + ( tps * ( 1 - exp ) );
+     }
++
 +    // Paper start - Further improve server tick loop
-+    private static final int TPS = 20;
 +    private static final long SEC_IN_NANO = 1000000000;
-+    public static final long TICK_TIME = SEC_IN_NANO / TPS;
 +    private static final long MAX_CATCHUP_BUFFER = TICK_TIME * TPS * 60L;
-+    private static final int SAMPLE_INTERVAL = 20;
++    private long lastTick = 0;
++    private long catchupTime = 0;
 +    public final RollingAverage tps1 = new RollingAverage(60);
 +    public final RollingAverage tps5 = new RollingAverage(60 * 5);
 +    public final RollingAverage tps15 = new RollingAverage(60 * 15);
-+    public double[] recentTps = new double[3]; // Paper - Fine have your darn compat with bad plugins
 +
 +    public static class RollingAverage {
 +        private final int size;
@@ -89,18 +91,18 @@ index c72bdd29d1..687250c639 100644
 +        public double getAverage() {
 +            return total / time;
 +        }
-     }
--    // Spigot End
++    }
 +    // Paper End
+     // Spigot End
  
      public void run() {
-         try {
 @@ -0,0 +0,0 @@ public abstract class MinecraftServer implements IAsyncTaskHandler, IMojangStati
  
                  // Spigot start
                  Arrays.fill( recentTps, 20 );
 -                long lastTick = System.nanoTime(), catchupTime = 0, curTime, wait, tickSection = lastTick, tickCount = 1;
-+                long start = System.nanoTime(), lastTick = start - TICK_TIME, catchupTime = 0, curTime, wait, tickSection = start; // Paper - Further improve server tick loop
++                long start = System.nanoTime(), curTime, wait, tickSection = start; // Paper - Further improve server tick loop
++                lastTick = start - TICK_TIME; // Paper
                  while (this.isRunning) {
                      curTime = System.nanoTime();
 -                    wait = TICK_TIME - (curTime - lastTick) - catchupTime;
@@ -151,11 +153,11 @@ index c72bdd29d1..687250c639 100644
  
 -                    MinecraftServer.currentTick = (int) (System.currentTimeMillis() / 50); // CraftBukkit
 +                    //MinecraftServer.currentTick = (int) (System.currentTimeMillis() / 50); // CraftBukkit // Paper - don't overwrite current tick time
-                     this.v();
+                     this.a(this::aT);
                      this.aa += 50L;
                      // Spigot end
 diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
-index 567af5b9fa..1c003a3898 100644
+index 6414f3d6b0..f066af3fe5 100644
 --- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
 +++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
 @@ -0,0 +0,0 @@ public final class CraftServer implements Server {