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/Do-not-let-armorstands-drown.patch

@@ -5,7 +5,7 @@ Subject: [PATCH] Do not let armorstands drown
 
 
 diff --git a/src/main/java/net/minecraft/server/EntityArmorStand.java b/src/main/java/net/minecraft/server/EntityArmorStand.java
-index 00a46129b8..6628af7778 100644
+index 5945e37a5..4ecf34a40 100644
 --- a/src/main/java/net/minecraft/server/EntityArmorStand.java
 +++ b/src/main/java/net/minecraft/server/EntityArmorStand.java
 @@ -0,0 +0,0 @@ public class EntityArmorStand extends EntityLiving {
@@ -20,7 +20,7 @@ index 00a46129b8..6628af7778 100644
      // Paper end
  }
 diff --git a/src/main/java/net/minecraft/server/EntityLiving.java b/src/main/java/net/minecraft/server/EntityLiving.java
-index d926cbb247..b9227f7a7f 100644
+index be0a3f38e..a6457e870 100644
 --- a/src/main/java/net/minecraft/server/EntityLiving.java
 +++ b/src/main/java/net/minecraft/server/EntityLiving.java
 @@ -0,0 +0,0 @@ public abstract class EntityLiving extends Entity {