* lisp/calendar/diary-lib.el: Use lexical-binding

* lisp/calendar/diary-lib.el: Use lexical-binding

(diary-pull-attrs): Avoid let...setq.
(diary-list-entries-2, diary-mark-entries-1)
(diary-font-lock-date-forms, diary-fancy-date-pattern):
Use calendar-dlet* around uses of diary-date-forms.
(list-only, number, date, entry): Don't declare globally.
(diary-including): Declare.
(diary-saved-point, date-string): Move before first use.
(diary-list-entries): Use calendar-dlet* around
diary-nongregorian-listing-hook and 'diary-list-entries-hook.
(displayed-year, displayed-month): Move before first use.
(diary-sexp-entry): Use calendar-let* around evaluation of the sexp.
(diary-remind): Use calendar-let* around evaluation of sexp.