Adding rosR and rosR_demos to documentation index for hydro and groovy

![rosr](https://f.cloud.github.com/assets/3089101/1860601/f219259e-77b5-11e3-93b1-e8d949aa5601.png)

We are happy to announce our ROS language extension for R, called rosR, for hydro as well as a demo package rosR_demos (for groovy and hydro). 

The aim of this contribution was to connect two previously separated worlds: robotic application development with the Robot Operating System (ROS) and statistical programming with R. This fruitful combination becomes apparent especially in the analysis and visualization of sensory data. We therefore introduce a new language extension for ROS that allows to implement nodes in pure R. All relevant aspects are described in a step-by-step development of a common sensor data transformation node. This includes the reception of raw sensory data via the ROS network, message interpretation, bag-file analysis, transformation and visualization, as well as the transmission of newly generated messages back into the ROS network.

Compare with: http://journal.r-project.org/archive/2013-2/dietrich-zug-kaiser.pdf