server deletes item after it hits 0
client handles empty stack size and switches quickbar inventory

item count string to "empty"
update INSTALL file
server tells client and client receives that an item should be spawned

client tells the world to spawn it, but that needs implementation.
make client actually handle that new packet type of item spawning

and register the entity to the renderer
torches spawn at player position now(TODO at mouse position)
make light renderer use an std::vector<Torch*>*, we were copying

which of course then the light renderer wouldn't see updates, and it's
a horribly expensive/pointless process. i made the same mistake with chunking
and then i wondered why sending a chunk took 300ms :D