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/0097-Location.isChunkLoaded-API.patch

@@ -1,14 +1,14 @@
-From 2b2f63ce1bf3c15f8688b6fb80eed9a83b292114 Mon Sep 17 00:00:00 2001
+From d6c9115f6181f8d5f7a3e9e9633726599d1b384e Mon Sep 17 00:00:00 2001
 From: Aikar <aikar@aikar.co>
 Date: Mon, 30 Apr 2018 19:27:31 -0400
 Subject: [PATCH] Location.isChunkLoaded() API
 
 
 diff --git a/src/main/java/org/bukkit/Location.java b/src/main/java/org/bukkit/Location.java
-index 5c3d42cc..1ddebf3c 100644
+index 6cffda15..a2dfad2f 100644
 --- a/src/main/java/org/bukkit/Location.java
 +++ b/src/main/java/org/bukkit/Location.java
-@@ -491,6 +491,7 @@ public class Location implements Cloneable, ConfigurationSerializable {
+@@ -506,6 +506,7 @@ public class Location implements Cloneable, ConfigurationSerializable {
          return this;
      }
  
@@ -17,5 +17,5 @@ index 5c3d42cc..1ddebf3c 100644
      public boolean equals(Object obj) {
          if (obj == null) {
 -- 
-2.20.1
+2.21.0