build 180621. serial port input device continuous independent brake control, scenery item selection and info, minor bug fixes, tweaks and refactoring

scenenode.cpp

@@ -762,4 +762,11 @@ basic_node::radius_() {
 }
 
 } // scene
+
+namespace editor {
+
+scene::basic_node const *Node { nullptr }; // temporary helper, currently selected scene node
+
+} // editor
+
 //---------------------------------------------------------------------------