Allow PXPhysicals to change scene nodes (cherry picked from H'uru 1b6f315186)

If this isn't done, the client will crash on exit when markers have been
loaded at some point in the game

MOULOpenSourceClientPlugin/Plasma20/Sources/Plasma/PubUtilLib/plPhysX/plPXPhysical.cpp

@@ -999,7 +999,18 @@ plKey plPXPhysical::GetSceneNode() const
 
 void plPXPhysical::SetSceneNode(plKey newNode)
 {
-	// Not Supported
+    plKey oldNode = GetSceneNode();
+    if (oldNode == newNode)
+        return;
+
+    // If we don't do this, we get leaked keys and a crash on exit with certain clones
+    // Note this has nothing do to with the world that the physical is in
+    if (newNode) {
+        plNodeRefMsg* refMsg = new plNodeRefMsg(newNode, plNodeRefMsg::kOnRequest, -1, plNodeRefMsg::kPhysical);
+        hsgResMgr::ResMgr()->SendRef(GetKey(), refMsg, plRefFlags::kActiveRef);
+    }
+    if (oldNode)
+        oldNode->Release(GetKey());
 }
 
 /////////////////////////////////////////////////////////////////////