Work towards using room positions rather than room links in placements

src/Dodge/LevelGen/Data.hs

@@ -119,7 +119,8 @@ assigning no bounds will allow rooms to overlap.
  -}
 data Room = Room
     { _rmPolys  :: [ [Point2] ]
-    , _rmLinks  :: [(Point2,Float)]
+    , _rmLinks  :: [(Point2,Float)] 
+        -- update the room when assigning the next link to an adjacent room with the head of of this list, return the tail
     , _rmLinkEff :: [(Point2,Float) -> Room -> Room]
     , _rmPos    :: [RoomPos]
     , _rmPath   :: [(Point2, Point2)]
@@ -142,6 +143,7 @@ data RoomWire
 data RoomPos 
     = OutLink Int    Point2  Float
     | InLink  Point2 Float
+    | UnusedLink Point2 Float
     | PosPl   Point2 Float
     | LabPos  Int    RoomPos
   deriving (Eq,Ord,Show)