Incomplete exploit fix in BiblioUpdateInv

[Exopteron]

My fix for the exploit within BiblioUpdateInv was incomplete. It's possible to bypass the safety check.

Steps:

Create an Atlas ItemStack with the Inventory NBT field containing the item you wish to create.
Create another Atlas ItemStack and add the previous one to this new stack's Inventory field.

Fix:
Rewrite BiblioUpdateInv to no longer send an ItemStack.
The packets' behavior can most likely be replicated another way.