(diary-file, american-date-diary-pattern)

(diary-file, american-date-diary-pattern)
(european-date-diary-pattern,european-calendar-display-form)
(american-calendar-display-form, diary-display-hook): Doc fixes.
(european-calendar-style): Doc fix.  Use calendar-set-date-style for
custom :set.  Mark as obsolete.
(calendar-date-style, iso-date-diary-pattern)
(iso-calendar-display-form): New user variables.
(diary-date-forms, calendar-date-display-form): Set using
calendar-date-style.  Doc fix.
(calendar-set-date-style): New command.
(european-calendar, american-calendar): Use calendar-set-date-style.
Mark as obsolete.