Grid.js static grid

This object added to OccupancyGridClient a grid map.

An example of code for run this code:
this.gridClient = new ROS2D.OccupancyGridClient({
     ros: ros,
     rootObject: viewer2D.scene
});
// Add grid to map
var gridMap = new ROS2D.Grid({
     size: 10,
     cellSize: 0.05
});
this.gridClient.rootObject.addChild(gridMap);

---
In my video, I show this grid in action on tablet, and PC.
https://www.youtube.com/watch?v=fhCHS7ibFrw

I have not tried this object with a /map received from ROS

![ipadview](https://cloud.githubusercontent.com/assets/4551246/2870124/d3f249ca-d2ae-11e3-851f-fa0d8acbddef.png)