Generate heal location constants automatically, move data back to a single file.

data/maps/DewfordTown/map.json

@@ -172,12 +172,5 @@
       "player_facing_dir": "BG_EVENT_PLAYER_FACING_ANY",
       "script": "DewfordTown_EventScript_HallSign"
     }
-  ],
-  "heal_locations": [
-    {
-      "id": "HEAL_LOCATION_DEWFORD_TOWN",
-      "x": 2,
-      "y": 11
-    }
   ]
 }