- Added TLandscape.OnMapChanged to handle changes to map tiles

- Reenabled terrain, statics, nodraw and flat toggles
- Fixed editing target list generation (in OnMouseUp) to only consider "normal" tiles, use their correct new order and the CanBeEdited attribute
- Removed obsolete TfrmMain.CanBeModified

Client/UfrmMain.lfm

@@ -946,6 +946,7 @@ object frmMain: TfrmMain
       ParentShowHint = False
       ShowHint = True
       Style = tbsCheck
+      OnClick = tbTerrainClick
     end
     object tbStatics: TToolButton
       Left = 300
@@ -957,6 +958,7 @@ object frmMain: TfrmMain
       ParentShowHint = False
       ShowHint = True
       Style = tbsCheck
+      OnClick = tbStaticsClick
     end
     object tbSeparator4: TToolButton
       Left = 369