Support Chinese diary entries in calendar and diary

Support Chinese diary entries in calendar and diary

* doc/emacs/cal-xtra.texi (Non-Gregorian Diary): Document new features for
Chinese calendar and diary.

* etc/NEWS: Mention support for Chinese dates in calendar and diary.

* lisp/calendar/cal-china.el (calendar-chinese-month-name-array): New var.
(calendar-chinese-from-absolute-for-diary)
(calendar-chinese-to-absolute-for-diary)
(calendar-chinese-mark-date-pattern, diary-chinese-mark-entries)
(diary-chinese-list-entries): New functions to list and mark
Chinese diary entries in the calendar window.
(diary-chinese-anniversary)
(diary-chinese-insert-anniversary-entry)
(diary-chinese-insert-entry, diary-chinese-insert-monthly-entry)
(diary-chinese-insert-yearly-entry): New commands to insert
Chinese diary entries.

* lisp/calendar/cal-menu.el (cal-menu-diary-menu): Add entries for
inserting Chinese diary entries.

* lisp/calendar/calendar.el (diary-chinese-entry-symbol): New
customizable variable.
(calendar-mode-map): Add bindings for inserting Chinese diary
entries.

* lisp/calendar/diary-lib.el (diary-font-lock-keywords): Support
font-locking Chinese dates.

Fixes: debbugs:17393