More map editor normalization, because people will doo whatever they can to break the system

android/assets/jsons/TileImprovements.json

@@ -73,6 +73,7 @@
 	},
 	{
 		name:"Fishing Boats",
+		terrainsCanBeBuiltOn:["Coast"],
 		food:1,
 		techRequired:"Sailing",
 		improvingTech:"Compass",

core/src/com/unciv/ui/mapeditor/TileEditorOptionsTable.kt

@@ -347,11 +347,14 @@ class TileEditorOptionsTable(val mapEditorScreen: MapEditorScreen): Table(Camera
             }
             else {
                 val improvement = tileInfo.getTileImprovement()!!
+                if(tileInfo.getBaseTerrain().impassable) tileInfo.improvement=null
                 if (improvement.terrainsCanBeBuiltOn.isNotEmpty() // for "everywhere" improvements like city ruins, encampments, ancient ruins
                         && improvement.terrainsCanBeBuiltOn.none { it == tileInfo.baseTerrain || it == tileInfo.terrainFeature })
                     tileInfo.improvement = null
             }
         }
+        if(tileInfo.getBaseTerrain().impassable || tileInfo.isWater)
+            tileInfo.roadStatus=RoadStatus.None
     }