tree starts to work. 'M' lists internal gocui tree

Signed-off-by: Jeff Carr <jcarr@wit.com>

widget.go

@@ -29,6 +29,21 @@ func initWidget(n *tree.Node) *guiWidget {
 		w.heights = make(map[int]int) // how wide each column in the grid is
 	}
 
+	p := n.Parent
+	if p == nil {
+		log.Log(ERROR, "parent == nil", w.String(), n.WidgetId, w.WidgetType)
+		return w
+	}
+	if p.TK == nil {
+		log.Log(ERROR, "parent.TK == nil", w.String(), n.WidgetId, w.WidgetType)
+		return w
+	}
+
+	// set the parent and append to parent children
+	var ptk *guiWidget
+	ptk = p.TK.(*guiWidget)
+	w.parent = ptk
+	ptk.children = append(ptk.children, w)
 	return w
 }