Openni 2.2 drivers

[RaresAmbrus]

This pull request integrates the openni 2.2 drivers in scitos robot. For now I've kept the binaries as well, just in case they will be needed, but they are not used; instead I've linked the project to the Openni2.2 git repository. When checking this project out you will have to run (in the root of the project): git submodule init git submodule update This will download the Openni 2.2 repository, which will be compiled along with the rest of the project (note that compilation will take some time, about 2-3 minutes, but this only needs to be done once).

[RaresAmbrus]

I've added a couple of arguments to scitos_bringup:

• in case the feeds of the cameras come in the wrong order (i.e. the chest camera is published under xtion_head, and the other way around) use the argument inverted:=yes
• to disable the chest camera use the argument with_chest_camera:=false

Right now I can say that the driver works "almost all the time" with 2 cameras. Sometimes at startup the depth feed of one of the cameras is not published - in that case restart scitos_bringup. In addition, when launching the 2d navigation and all the processes, the framerate of one of the cameras goes down; I still can't tell whether this is from having too many process running at the same time, or from pushing too many messages in ros, or simply from the driver. I have however tested the driver with 2 cameras on the robot, and without any other process running the framerate doesn't drop.