prepare for hexagon display & other models

- display cell as hexagon is Display.mHexagon if set ( not default )
will need a checkbox to set this
- various new models preparation...

java/org/artisanlogiciel/games/maze/persist/MazePersistRaw.java

@@ -4,8 +4,13 @@ import org.artisanlogiciel.games.maze.LabyModel;
 
 import java.io.*;
 
+/**
+ * raw model with short table inner of LabyModel
+ */
 public class MazePersistRaw
 {
+    private static byte HEADER[] = new byte[]{(byte) 'L', (byte) 'A', (byte) 'B', (byte) '0'};
+
     private LabyModel model;
 
     public MazePersistRaw(LabyModel model)
@@ -24,7 +29,7 @@ public class MazePersistRaw
             // first raw format, not smart.
             DataOutputStream dataOut = new DataOutputStream(pOut);
             // should dump this to stream.
-            dataOut.write(new byte[]{(byte) 'L', (byte) 'A', (byte) 'B', (byte) '0'});
+            dataOut.write(HEADER);
             dataOut.writeInt(model.getWidth());
             dataOut.writeInt(model.getHeight());
             dataOut.flush();
@@ -46,6 +51,7 @@ public class MazePersistRaw
             byte[] header = new byte[4];
             DataInputStream in = new DataInputStream(pIn);
             in.read(header);
+            // TODO check header == HEADER
             int rwidth = in.readInt();
             int rheight = in.readInt();
             if ((rwidth > 0) && (rheight > 0)) {