Made it more clear what operations happens in MergedList
Added support for null compound tags because minecraft renders the items as "+ 3 NBT tags"
fixed ++ on wrong side of variable
Updated PacketOutWindowItems, added constructor & reformatter file
Renamed handler to inventoryHandler & Depraceted inventory field, changed the field visibility to private, added getter
 and updated all references to it to use the getter
Removed a few unused imports inside PacketOutRespawn
Added .equals(Object) & .hashCode()
Removed unneeded tags from ItemStack
Added a few testing items
Added player.world field, this will be used when we support multiple worlds
Added missing constructor
Added .equals() & .hashCode() to ItemStack
Changed structure of Inventories, every Inventory implements the Inventory interface, the DefaultInventory gives the
 default implementation of a Inventory.
Added support for players pressing Q to drop a item, or using a number on keyboard to swap the items on the hot bar.
Still no support for remembering when items are moved.