root does not marshal TSs on todos, always on schedules, dones. Test.

pttodo/root.go

@@ -36,3 +36,17 @@ func (root *Root) MergeIn(root2 Root) {
 		}
 	}
 }
+
+func (root Root) MarshalYAML() (interface{}, error) {
+	for i := range root.Todo {
+		root.Todo[i].writeTS = false
+	}
+	for i := range root.Scheduled {
+		root.Scheduled[i].writeTS = true
+	}
+	for i := range root.Done {
+		root.Done[i].writeTS = true
+	}
+	type Alt Root
+	return (Alt)(root), nil
+}