Fix miscalculated keyboard height with number row

The 'keysHeight' field needs to be updated. As this class is not
intended to be mutable, copy the list of rows and call the constructor.

Also remove an unecessary component of the keyboard height calculation.

srcs/juloo.keyboard2/Keyboard2View.java

@@ -229,7 +229,6 @@ public class Keyboard2View extends View
     int width = dm.widthPixels;
     int height =
       (int)(_config.keyHeight * _keyboard.keysHeight
-          + _keyboard.rows.size()
           + _config.marginTop + _config.margin_bottom);
     setMeasuredDimension(width, height);
     _keyWidth = (width - (_config.horizontal_margin * 2)) / _keyboard.keysWidth;

srcs/juloo.keyboard2/KeyboardData.java

@@ -74,8 +74,9 @@ class KeyboardData
 
   public KeyboardData addNumberRow()
   {
-    rows.add(0, number_row.updateWidth(keysWidth));
-    return this;
+    ArrayList<Row> rows_ = new ArrayList<Row>(this.rows);
+    rows_.add(0, number_row.updateWidth(keysWidth));
+    return new KeyboardData(rows_, keysWidth);
   }
 
   public Key findKeyWithValue(KeyValue kv)