Add java.util.random seed as initial parameter

- prepare for short save allowing to fully recreate initial lab
having only seed and x,y,depth paramters

java/org/artisanlogiciel/games/MazeParamsFixed.java

@@ -4,6 +4,7 @@ import java.io.File;
 
 public class MazeParamsFixed implements MazeParams
 {
+    long seed;
     int width;
     int height;
     int maxdepth;
@@ -27,10 +28,16 @@ public class MazeParamsFixed implements MazeParams
 	maxdepth=MD;
     }
 
-    public MazeParamsFixed(File saveDir, int W, int H, int MD)
+    public MazeParamsFixed(File saveDir, int W, int H, int MD, long seed)
     {
 	name = null;
 	setParams(saveDir,W,H,MD);
+	this.seed=seed;
+    }
+
+    public long getSeed()
+    {
+        return seed;
     }
 
     public int getWidth()