* lisp/cus-edit.el: Use lexical-binding.
(customize-push-and-save, customize-apropos)
(custom-buffer-create-internal): Use closures.
* lisp/progmodes/bat-mode.el (bat-mode-syntax-table): "..." are strings.
* lisp/progmodes/ada-xref.el: Use setq.
* lisp/net/tramp.el (with-tramp-progress-reporter): Avoid setq.
* lisp/dframe.el: Use lexical-binding.
(dframe-frame-mode): Fix calling convention for hooks. Use a closure.
* lisp/speedbar.el (speedbar-frame-mode): Adjust call accordingly.
* lisp/descr-text.el: Use lexical-binding.
(describe-text-widget, describe-text-sexp, describe-property-list):
Use closures.
* lisp/comint.el (comint-history-isearch-push-state): Use a closure.
* lisp/calculator.el: Use lexical-binding.
(calculator-number-to-string): Make it work with lexical-binding.
(calculator-funcall): Same and use cl-letf.
