- Fixed a bug with Inventory#add(Item) not handling integer overflow properly.
- Fixed a bug with Inventory#add(Item) returning an Item object with an amount of 0 instead of null.
- Inventory#add(Item) now returns an Optional<Item> object and cleaned up portions of the method.
- code clean-up to Inventory#remove(int, int).
- Inventory#remove(int, int) now supports stopping and refiring of listeners while the inventory is being updated (prevents flickering and unnecessary updating of the inventory for batch updates).