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/model/BooleanLongSet.java

@@ -0,0 +1,41 @@
+package org.artisanlogiciel.games.maze.model;
+
+/**
+ * store an array booleans in a long
+ */
+
+public class BooleanLongSet {
+
+    long[] internal;
+
+    // 62 bits for long, 2 bits reserved
+    int USED_BITS = 62;
+    int width;
+
+    public BooleanLongSet(int width, int USED_BITS)
+    {
+        internal = new long[width];
+        this.width = width;
+        this.USED_BITS = USED_BITS;
+    }
+
+    boolean isSet(int x) {
+        int group = x / USED_BITS;
+        if (group < width) {
+            int pos = x % USED_BITS;
+            long mask = 1 << pos;
+            return (internal[group] & mask) != 0;
+        }
+        return false;
+    }
+
+    void set(int x, boolean value)
+    {
+        int group = x / USED_BITS;
+        if (group < width) {
+            int pos = x % USED_BITS;
+            long mask = 1 << pos;
+            internal[group] &= mask;
+        }
+    }
+}