Merge branch 'master' into pre/1.13

* master:
  Relookup Entity Save ID if was null during precache

Spigot-Server-Patches/Fix-Old-Sign-Conversion.patch

@@ -25,11 +25,11 @@ index 785a1a2184..528db8704e 100644
                                  }
  
 diff --git a/src/main/java/net/minecraft/server/TileEntity.java b/src/main/java/net/minecraft/server/TileEntity.java
-index e03965fc7c..9ad14417e3 100644
+index d8d519143e..6021a3401f 100644
 --- a/src/main/java/net/minecraft/server/TileEntity.java
 +++ b/src/main/java/net/minecraft/server/TileEntity.java
 @@ -0,0 +0,0 @@ import org.bukkit.inventory.InventoryHolder; // CraftBukkit
- public abstract class TileEntity implements KeyedObject {
+ public abstract class TileEntity implements KeyedObject { // Paper
  
      public Timing tickTimer = MinecraftTimings.getTileEntityTimings(this); // Paper
 +    boolean isLoadingStructure = false; // Paper