Use `lexical-binding` in all the cal-*.el files
* lisp/calendar/cal-bahai.el: Use lexical-binding. (calendar-bahai-date-string): Use `calendar-dlet*`. * lisp/calendar/cal-china.el: Use lexical-binding. (calendar-chinese-zodiac-sign-on-or-after) (calendar-chinese-new-moon-on-or-after): Declare `year`. (calendar-chinese-from-absolute-for-diary) (calendar-chinese-to-absolute-for-diary) (calendar-chinese-mark-date-pattern): Avoid dynbound var `date` as function argument. * lisp/calendar/cal-coptic.el: Use lexical-binding. (calendar-coptic-date-string): Use `calendar-dlet*`. (calendar-ethiopic-to-absolute, calendar-ethiopic-from-absolute) (calendar-ethiopic-date-string, calendar-ethiopic-goto-date): Avoid dynbound var `date` as function argument. * lisp/calendar/cal-french.el: Use lexical-binding. * lisp/calendar/cal-hebrew.el: Use lexical-binding. (holiday-hebrew-hanukkah): Don't use the third form in `dotimes`. * lisp/calendar/cal-islam.el: Use lexical-binding. (calendar-islamic-to-absolute): Comment out unused vars `month` and `day`. * lisp/calendar/cal-move.el: * lisp/calendar/cal-mayan.el: * lisp/calendar/cal-iso.el: Use lexical-binding. * lisp/calendar/cal-persia.el: Use lexical-binding. (calendar-persian-date-string): Use `calendar-dlet*`. * lisp/calendar/cal-html.el: Use lexical-binding. (cal-html-insert-minical): Comment out unused var `date`. (cal-html-cursor-month, cal-html-cursor-year): Mark `event` arg as unused. * lisp/calendar/cal-menu.el: Use lexical-binding. (diary-list-include-blanks): Declare var. * lisp/calendar/cal-x.el: Use lexical-binding. * lisp/calendar/cal-tex.el: Use lexical-binding. (diary-list-include-blanks): Declare var. (cal-tex-insert-days, cal-tex-cursor-week-iso, cal-tex-week-hours) (cal-tex-weekly-common, cal-tex-cursor-filofax-2week) (cal-tex-cursor-filofax-daily, cal-tex-daily-page): Declare `date` as dynbound for the benefit of `cal-tex-daily-string`.