simplify tree "rebalancing"

We now unconditionally ensure that the graph is a tree (as it should),
by always removing the parent from the target node, and reconnecting
said node to the new transformation.

The very complex implementation currently there did not seem to be needed.

src/TransformerGraph.cpp

@@ -549,36 +549,14 @@ bool TransformerGraph::setTransformation(osg::Node &transformer,const std::strin
     }
     else if (target->getParent(0) != source)
     {
-        if (target == &transformer || (source->getParent(0) == &transformer && target->getParent(0) != &transformer))
+        if (target == &transformer)
         {
             invertOSGTransform(trans, quat, source, target, source_frame, target_frame);
         }
 
-        if (target->getParent(0) != &transformer)
-        {
-            std::set<osg::Node*> ancestors;
-            osg::ref_ptr<osg::Node> sourceAncestor = source;
-            while (sourceAncestor != &transformer)
-            {
-                ancestors.insert(sourceAncestor);
-                if (sourceAncestor->getParent(0) == target)
-                {
-                    target->removeChild(sourceAncestor);
-                    getTransform(&transformer)->addChild(sourceAncestor);
-                    ancestors.clear();
-                    break;
-                }
-                else
-                    sourceAncestor = sourceAncestor->getParent(0);
-            }
-
-            ::makeRoot(transformer, getTransform(target), ancestors);
-
-        }
-
-	osg::ref_ptr<osg::Node> node = target; //insures that node is not deleted
-        removeFrame(transformer,target_frame);
-        source->addChild(node);
+        osg::ref_ptr<osg::Node> node = target; //insures that node is not deleted
+        target->getParent(0)->removeChild(target);
+        source->addChild(target);
     }
 
     target->setAttitude(quat);