refactoring, deploy Position and XYGridIterator

- try to use more Position instead of (x,y)
  - create PositionWithDpeth for its specific usage in path finding
- create a XYGridITerator that walk cells from grid X then Y.

java/org/artisanlogiciel/games/maze/gui/MazeControler.java

@@ -229,6 +229,11 @@ public class MazeControler extends JPanel {
         return newActionButton("load", format, action);
     }
 
+    private JPanel createPaletteChooser()
+    {
+        return new JPanel(new FlowLayout());
+    }
+
     private JPanel createResolveQuitBar() {
         JPanel resolveQuitBar = new JPanel(new FlowLayout());
 
@@ -388,6 +393,7 @@ public class MazeControler extends JPanel {
                 display.setAutoSize(autoSlide.isSelected());
             }
         });
+
         final JCheckBox hexagon = new JCheckBox("hexagon");
         hexagon.addChangeListener(new ChangeListener() {
             public void stateChanged(ChangeEvent e) {
@@ -395,11 +401,19 @@ public class MazeControler extends JPanel {
             }
         });
 
+        final JCheckBox background = new JCheckBox("background");
+        background.addChangeListener(new ChangeListener() {
+            public void stateChanged(ChangeEvent e) {
+                display.setBackground(background.isSelected());
+            }
+        });
+
         JPanel resizecontrol = new JPanel(new FlowLayout());
         resizecontrol.add(showAll);
         resizecontrol.add(slider);
         resizecontrol.add(autoSlide);
         resizecontrol.add(hexagon);
+        resizecontrol.add(background);
 
         return resizecontrol;