2D navigation with orientation

Hi,

I've extended the nav2djs interface with the possibility to send the robot to a goal position at a particular orientation. The double-click behavior is still the the default behavior of the tool. However, if you set the option `withOrientation` you can switch to a click-and-point behavior, that is, you click a mouse button, point into the desired direction while the mouse button is still pressed, and release it when you are happy with the orientation. Below you find a screenshot of the interface.

Please note that I am new to webtools and JavaScript in general. So any feedback is more than welcome. Thanks for the nice tools that you have provided!

cheers,
Lars

![nav2djs_withorientation](https://f.cloud.github.com/assets/4312427/752687/d0235238-e54e-11e2-8062-20abefd7c0e9.png)