* calendar/todos.el: (todos-set-show-current-file): Rename from
todos-toggle-show-current-file and adjust callers.
(todos-number-priorities): Rename from todos-number-prefix and
adjust users.
(todos-update-count): Rename from todos-set-count and adjust
callers.
(todos-hide-show-item-numbering): Rename from
todos-toggle-item-numbering and adjust callers.
(todos-hide-show-done-items): Rename from
todos-toggle-view-done-items and adjust callers.
(todos-show-done-only): Rename from todos-toggle-show-done-only.
(todos-view-archived-items): Comment out.
(todos-show-archive): Prompt to choose another archive file if
current Todos file lacks an archive; prompt to visit archive
anyway when current category has no archived items.