* calendar/todos.el (todos-insert-item): Fix last change to make

* calendar/todos.el (todos-insert-item): Fix last change to make
sure calling insertion "here" from outside goal todo items section
gives new item top priority.  With priority insertion, if user
cancels before setting priority, restore display.
(todos-find-item): Restore narrowing after searching.
(todos-item-done): Allow adding (same) comment to marked items.
Don't add empty comment to done item.