Adapter to use the ARToolKit inside OpenSceneGraph

OSGART is a library that simplifies the development of Augmented Reality or Mixed Reality applications by combining the well-known ARToolKit tracking library with OpenSceneGraph. But rather than acting just as a simple nodekit, the library offers 3 main functionalities: high level integration of video input (video object, shaders), spatial registration (marker-based, multiple trackers), and photometric registration (occlusion, shadow).