Update upstream BD/B/CB/S

Note to other developers: This commit may require you to wipe your
workspace as a result of the changes to BD.

--- work/BuildData
Submodule work/BuildData f527a8ff..d56672db:
  > Mappings Update

--- work/Bukkit
Submodule work/Bukkit 0c1d258bb..db06c80d7:
  > Add list of entities to EntityTransformEvent
  > SPIGOT-4347: Add API to allow storing arbitrary values on ItemStacks

---work/CraftBukkit
Submodule work/CraftBukkit 6a398ac44..068dab5be:
  > Enable optional source JAR shading via profile shadeSourcesJar
  > Use ImmutableList rather than AbstractList for CraftMetaBook
  > Fix setRecipes(List) not setting Knowledge Book recipes.
  > Mappings Update
  > Add list of entities to EntityTransformEvent & move die calls
  > SPIGOT-4347: Add API to allow storing arbitrary values on ItemStacks
  > Add Vanilla help to default permissions

--- work/Spigot
Submodule work/Spigot a1f2566f6..e769fe4d9:
  > Mappings Update
  > Rebuild patches

Spigot-Server-Patches/Add-configurable-despawn-distances-for-living-entiti.patch

@@ -5,7 +5,7 @@ Subject: [PATCH] Add configurable despawn distances for living entities
 
 
 diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
-index 341038fc4d..3e1f4be10f 100644
+index 341038fc4..3e1f4be10 100644
 --- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
 +++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
 @@ -0,0 +0,0 @@ public class PaperWorldConfig {
@@ -30,7 +30,7 @@ index 341038fc4d..3e1f4be10f 100644
 +    }
  }
 diff --git a/src/main/java/net/minecraft/server/EntityInsentient.java b/src/main/java/net/minecraft/server/EntityInsentient.java
-index cc74150dae..9e95ede7fe 100644
+index 9d4d8c697..8f4319c80 100644
 --- a/src/main/java/net/minecraft/server/EntityInsentient.java
 +++ b/src/main/java/net/minecraft/server/EntityInsentient.java
 @@ -0,0 +0,0 @@ public abstract class EntityInsentient extends EntityLiving {