Added: on a phone with a physical Menu key, that key opens the settings while
the clock is on screen. It is the only key the clock takes — Back, Home and the
volume rocker all reach the system untouched.

Changed: a tap on the clock dims the screen, and the next tap gives it back, for
the clock left running beside the bed. Only the clock's own window is dimmed:
the phone's brightness setting is not touched, no permission is asked for, and
giving it back hands the screen to whatever the phone itself is set to.

Changed: the menu is behind a long press now rather than a tap, and it carries
"Close the clock" — on a phone driven by gestures there may be no Back button
and no navigation bar to leave a full-screen clock with.

Changed: in landscape with the calendar off, the date is a line under the clock
rather than a column beside it, so the time has the whole width. The order of
that line — weekday, month and day, year, seconds — is set by dragging in the
general settings.
