Updated Upstream (Bukkit/CraftBukkit/Spigot)

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

Please note that this build includes changes to meet upstreams
requirements for nullability annotations. While we aim for a level of
accuracy, these might not be 100% correct, if there are any issues,
please speak to us on discord, or open an issue on the tracker to
discuss.

Bukkit Changes:
9a6a1de3 Remove nullability annotations from enum constructors
3f0591ea SPIGOT-2540: Add nullability annotations to entire Bukkit API

CraftBukkit Changes:
8d8475fc SPIGOT-4666: Force parameter in HumanEntity#sleep
8b1588e2 Fix ExplosionPrimeEvent#setFire not working with EnderCrystals
39a287b7 Don't ignore newlines in PlayerListHeader/Footer

Spigot Changes:
cf694d87 Add nullability annotations

Spigot-API-Patches/0085-Tameable-getOwnerUniqueId-API.patch

@@ -1,4 +1,4 @@
-From 1cbb7e853c6b79fe56bb48056ef19cbf83e4a85f Mon Sep 17 00:00:00 2001
+From ec25fb2dc8987362a3aa99baf07baa8fd2a79ba9 Mon Sep 17 00:00:00 2001
 From: Aikar <aikar@aikar.co>
 Date: Sat, 24 Feb 2018 00:55:52 -0500
 Subject: [PATCH] Tameable#getOwnerUniqueId API
@@ -7,10 +7,17 @@ This is faster if all you need is the UUID, as .getOwner() will cause
 an OfflinePlayer to be loaded from disk.
 
 diff --git a/src/main/java/org/bukkit/entity/Tameable.java b/src/main/java/org/bukkit/entity/Tameable.java
-index 44497aa3..0987c1e8 100644
+index 0c066bdfc..be436f8df 100644
 --- a/src/main/java/org/bukkit/entity/Tameable.java
 +++ b/src/main/java/org/bukkit/entity/Tameable.java
-@@ -23,9 +23,21 @@ public interface Tameable extends Entity {
+@@ -1,5 +1,6 @@
+ package org.bukkit.entity;
+ 
++import org.jetbrains.annotations.NotNull;
+ import org.jetbrains.annotations.Nullable;
+ 
+ public interface Tameable extends Entity {
+@@ -25,9 +26,22 @@ public interface Tameable extends Entity {
       */
      public void setTamed(boolean tame);
  
@@ -20,6 +27,7 @@ index 44497aa3..0987c1e8 100644
 +     *
 +     * @return the owners UUID, or null if not owned
 +     */
++    @NotNull
 +    public java.util.UUID getOwnerUniqueId();
 +    // Paper end
 +
@@ -31,7 +39,7 @@ index 44497aa3..0987c1e8 100644
 +     *
       * @return the owning AnimalTamer, or null if not owned
       */
-     public AnimalTamer getOwner();
+     @Nullable
 -- 
-2.20.1
+2.21.0