Simplify day storage

The function day_process_storage() is a wrapper for day_store_items().
It has an unused second argument, and is only used twice to load the
selected day. It has been removed.

A new function, get_slctd_day(), is the equivalant of get_today() and
replaces the very awkwardly named ui_calendar_get_slctd_day_sec().

Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>

src/ui-calendar.c

@@ -193,12 +193,6 @@ struct date *ui_calendar_get_slctd_day(void)
 	return &slctd_day;
 }
 
-/* Returned value represents the selected day in calendar (in seconds) */
-time_t ui_calendar_get_slctd_day_sec(void)
-{
-	return date2sec(slctd_day, 0, 0);
-}
-
 static int ui_calendar_get_wday(struct date *date)
 {
 	struct tm t;