Problem:
Since 24cb11a, the Forge event ItemPickupEvent has been used to notify the pickup count of new items. ItemPickupEvent is called on the logical server only. If the client is a slave (connected to a dedicated server), the event is not triggered.

Solution:
The ItemPickupEvent handler should send a message to the logical client using the same mechanism as pre- 24cb11a. The message handler should be the one to update the client list.

It should be easy to keep the original message format. Then we can support servers running [,1.4] and [current,].