Revert "- removed STAT_INVENTORY."

This reverts commit 5ff0abe568.

- use STAT_INVENTORY only for held items.

Seems this was causing some strange issues with hubs, but for items placed in the world it still cannot be allowed to have them in a different statnum.

src/g_shared/a_pickups.cpp

@@ -821,6 +821,7 @@ void AInventory::BecomeItem ()
 	}
 	RemoveFromHash ();
 	flags &= ~MF_SPECIAL;
+	ChangeStatNum(STAT_INVENTORY);
 	SetState (FindState("Held"));
 }
 
@@ -847,6 +848,7 @@ void AInventory::BecomePickup ()
 	}
 	flags = (GetDefault()->flags | MF_DROPPED) & ~MF_COUNTITEM;
 	renderflags &= ~RF_INVISIBLE;
+	ChangeStatNum(STAT_DEFAULT);
 	SetState (SpawnState);
 }