Update upstream B/CB/S

--- work/Bukkit
Submodule work/Bukkit 6eac6d70..1ef8b9d9:
  > Add Player#openBook(ItemStack) method

--- work/CraftBukkit
Submodule work/CraftBukkit 17543ecf..649921e5:
  > Add Player#openBook(ItemStack) method
  > SPIGOT-2000: Picking up items to shield slot working inconsistently when inventory is full
  > SPIGOT-5037: Player.openMerchant does not show merchant level
  > SPIGOT-5038: Inventory.getHolder returns null for wandering traders

--- work/Spigot
Submodule work/Spigot baafee91..df0eb250:
  > SPIGOT-5043: Desync if world is changed in PlayerSpawnLocationEvent
  > Rebuild patches

Implementation developer note:
This patch adds a "pre-source" patch system for fixing malformed patches
from upstream directly. This seems to keep happening so it's best we
have some way to deal with them. This system brings those issues into
our domain rather than needing to wait for upstream to fix their
malformed files.

Spigot-API-Patches/0010-Add-player-view-distance-API.patch

@@ -1,17 +1,18 @@
-From be074334b42c57876a13779e7d33b74087bdf90a Mon Sep 17 00:00:00 2001
+From 5bb98070c72a6c08bf15a002acbda0f5a23b203d Mon Sep 17 00:00:00 2001
 From: Byteflux <byte@byteflux.net>
 Date: Mon, 29 Feb 2016 18:05:37 -0600
 Subject: [PATCH] Add player view distance API
 
 
 diff --git a/src/main/java/org/bukkit/entity/Player.java b/src/main/java/org/bukkit/entity/Player.java
-index 6568b179d..338d47205 100644
+index f5d31648..a9b11322 100644
 --- a/src/main/java/org/bukkit/entity/Player.java
 +++ b/src/main/java/org/bukkit/entity/Player.java
-@@ -1486,6 +1486,20 @@ public interface Player extends HumanEntity, Conversable, OfflinePlayer, PluginM
+@@ -1477,6 +1477,20 @@ public interface Player extends HumanEntity, Conversable, OfflinePlayer, PluginM
+      * @param affects Whether the player can affect mob spawning
       */
-     public void updateCommands();
- 
+     public void setAffectsSpawning(boolean affects);
++
 +    /**
 +     * Gets the view distance for this player
 +     *
@@ -25,10 +26,9 @@ index 6568b179d..338d47205 100644
 +     * @param viewDistance the player's view distance
 +     */
 +    public void setViewDistance(int viewDistance);
-+
-     // Spigot start
-     public class Spigot extends Entity.Spigot
-     {
+     // Paper end
+ 
+     /**
 -- 
 2.21.0