Add indexed world modifications, example use in flicker lights

src/Dodge/Update.hs

@@ -58,6 +58,7 @@ functionalUpdate w = case _menuLayers w of
         . updateDoors
         . resetWorldEvents
         . dbArg _worldEvents
+        . updateModifications
         . updateParticles 
         . updateProjectiles 
         . updateLightSources
@@ -82,6 +83,11 @@ functionalUpdate w = case _menuLayers w of
       where 
         (x,y) = cloudZoneOfPoint $ stripZ $ _clPos cl
 
+updateModifications :: World -> World
+updateModifications w = foldr f w (_modifications w)
+  where
+    f md = _mdUpdate md md
+
 splinterBlock :: Block -> World -> World
 splinterBlock bl w = foldr unshadowBlock w (_blShadows bl) -- foldr shiftTowardCen w (_blWallIDs bl)
     & blocks . ix (_blID bl) . blHPs %~ tail