Updated Upstream (Bukkit/CraftBukkit)

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

Bukkit Changes:
b999860d SPIGOT-2304: Add LootGenerateEvent

CraftBukkit Changes:
77fd87e4 SPIGOT-2304: Implement LootGenerateEvent
a1a705ee SPIGOT-5566: Doused campfires & fires should call EntityChangeBlockEvent
41712edd SPIGOT-5707: PersistentDataHolder not Persistent on API dropped Item

Spigot-API-Patches/0055-Add-UnknownCommandEvent.patch

@@ -1,4 +1,4 @@
-From c9b7dd5b35264329e3f69140fb8845e44bd1b251 Mon Sep 17 00:00:00 2001
+From d601968fd5d4787245c961ce2abe9eba0803210b Mon Sep 17 00:00:00 2001
 From: Sweepyoface <github@sweepy.pw>
 Date: Sat, 17 Jun 2017 18:48:06 -0400
 Subject: [PATCH] Add UnknownCommandEvent
@@ -93,5 +93,5 @@ index 000000000..251342c3c
 +}
 +
 -- 
-2.25.1
+2.26.2