with a osg::DefaultUserDataContainer subclassed from this. The user object access methods have now all
been moved from osg::Object into the UserDataContainer class, except for the set/getUserData() methods
that are left in osg::Object for backwards compatibility, and the description list access methods have
been moved back into osg::Node.
main UserObject access methods are now all def
Refactored original UserData and Descriptions strings to be managed alongside the new user object suppport within
a single osg::Object::UserDataContainer.