Add option to ScitosA5 to generate openni stack topics

This adds a few things to be able to get all the topics of the normal openni camera in the simulator. The main drawback is that simulating the cameras in morse at this size and frequency is costly. However, I've found it to work out ok. The original settings are used if you do not set the flag when creating the robot. To run:

* Create a Scitosa5 robot in your scene with `Scitosa5(with_cameras = Scitosa5.WITH_OPENNI)`
* Launch `roslaunch strands_morse generate_camera_topics.launch`

If @kunzel could have a look at these changes before they are merge that would be great.