Added getBound() to begining of osgProducer::CameraGroup::frame() to ensure
that the parallel cull traversals don't all do a getBound().
Added osgProducer::CameraGroup::getTopMostSceneData() convinience method.
coord system.
Addition of ReadCameraConfigFile and WriteCameraConfigFile as a tempory
measure for implementing local a C++ read/write of the Producer::CameraConfig, this
will be removed once these implementations or similar have been moved to Producer.
