Make use hammers and item positions slightly more logical

src/Dodge/Creature/Action.hs

@@ -277,11 +277,11 @@ youDropItem' w = case yourItem w ^? _Just . itCurseStatus of
   where
     cr = you w
 
-{- | Copy an inventory item to the floor. -}
+{- | Copy an inventory item to the floor.  -}
 copyInvItemToFloor :: Creature -> Int -> World -> World
 copyInvItemToFloor cr i = copyItemToFloor (_crPos cr) 
     $ _crInv cr IM.! i 
-        & itInvPos .~ Nothing
+        & itPos .~ VoidItm
         & itIsHeld .~ False
 
 sizeSelf :: Float -> Creature -> World -> Maybe World