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/0059-Entity-fromMobSpawner.patch

@@ -1,16 +1,16 @@
-From e5a62fbf4f51754de1e49ce6046eefc76c317a73 Mon Sep 17 00:00:00 2001
+From c98cd92d19f14a732e1ac7e3e3922047e4dbf817 Mon Sep 17 00:00:00 2001
 From: BillyGalbreath <Blake.Galbreath@GMail.com>
 Date: Sun, 18 Jun 2017 18:17:05 -0500
 Subject: [PATCH] Entity#fromMobSpawner()
 
 
 diff --git a/src/main/java/org/bukkit/entity/Entity.java b/src/main/java/org/bukkit/entity/Entity.java
-index 015a4c56..13de2d74 100644
+index 69307e252..373204d37 100644
 --- a/src/main/java/org/bukkit/entity/Entity.java
 +++ b/src/main/java/org/bukkit/entity/Entity.java
-@@ -569,5 +569,12 @@ public interface Entity extends Metadatable, CommandSender, Nameable {
-      * @return Location where entity originates or null if not yet added
+@@ -591,5 +591,12 @@ public interface Entity extends Metadatable, CommandSender, Nameable {
       */
+     @Nullable
      Location getOrigin();
 +
 +    /**
@@ -22,5 +22,5 @@ index 015a4c56..13de2d74 100644
      // Paper end
  }
 -- 
-2.20.1
+2.21.0