Add IntMapHelper, locate wall cutting bug

src/Dodge/LevelGen/AutoDoor.hs

@@ -12,10 +12,10 @@ import Dodge.Creature.Property
 import Geometry
 import Picture
 import qualified DoubleStack as DS
+import qualified IntMapHelp as IM
 
 --import Data.List
 --import Data.Maybe
-import qualified Data.IntMap.Strict as IM
 import Control.Lens
 --import Control.DeepSeq (deepseq)
 
@@ -33,7 +33,7 @@ autoDoorAt
     -> IM.IntMap Wall
 autoDoorAt a b wls = IM.union wls $ IM.fromList $ zip is $ mkAutoDoor a b is
   where 
-    i = newKey wls
+    i = IM.newKey wls
     is = [i..]
 
 mkAutoDoor