* todos.el: Some custom cleanup.

* todos.el: Some custom cleanup.
(todos-edit): Rename from todos-item-insertion and adjust doc string.
(todos-display): Rename from todos-mode-display.
(todos-item-mark, todos-undo-item-omit-comment): Change :group to
todos-edit.
(todos-indent-to-here): Change :group to todos-display.
(todos, todos-edit, todos-categories, todos-filtered)
(todos-display, todos-faces): Change :version to "24.4".