R1:aa86cf0ed845

Countdown tweaks

Summary:
A few tweaks to hsb's Countdown implementation:

- Allow the page to be rendered "chromeless", suitable for display on one of
the dozens of monitors everyone has laying around.
- Show title of countdown in deletion dialog.
- When creating a new countdown default to time(), not Dec 31, 1969.
- Add extra "/" after editing to avoid needless redirect.
- Tweak some page titles.
- Show countdown author in list view.
- Highlight tab in list view.
- Tweak menu copy.