[misc] Formatting options

Calcurse has five formatting options, two of which are for recurring
appointments/events: --format-recur-apt and format-recur-event. In the man
page it is stated that the available fields (format specifiers) depend
on the item type.

The recurring items have some extra properties (e.g. a stop time), but
as far as formatting fields are concerned, there are no differences.
So why the special formatting options?

Why not use the formatting options --format-apt and --format-event for
the recurring ones as well? A separate format for recurring appointments
may then be accomplished by combining --filter-type and --format-apt.

Eliminating the two recurring formats would simplify the internal interfaces
(long argument lists).

What I miss is another format option, --format-inst-apt, for instant
appointments, i.e. appointments with zero duration, or otherwise put, with
end time equal to start time. At the moment it is not possible to format
the command line output from queries as done in the appointment panel for
instant appointments.

Lars Henriksen