[Design] Any time/all day change

[Jeffrey Harris]

Hi Folks,

Because anytime is actually a pretty common case, and because any time
wasn't very discoverable before, the default when double clicking in the
allday canvas is now to create an anytime event, not an allday event.
You can still check allday, of course.

A quick reminder about the difference between anytime and allday:

- Anytime is meant for events that don't have a specific time or
duration.  They don't take up any time on your calendar (so no little
blue mark in the minicalendar for anytime events).  It's rendered with a
light background in the calendar's allday canvas.

- Allday is meant for events that will be occupying lots of your time
that day.  One all-day event makes a full blue mark for that day in the
minicalendar.  It's rendered with a dark background in the calendar's
allday canvas.

Sincerely,
Jeffrey