Use lexical-binding in almost all of play/*.el
* lisp/play/5x5.el: Use lexical-binding.
(5x5-draw-grid-end, 5x5-draw-grid, 5x5-solver)
(5x5-solve-suggest): Silence byte-compiler.
* lisp/play/cookie1.el: Use lexical-binding.
(cookie-shuffle-vector, cookie-apropos): Silence byte-compiler.
* lisp/play/zone.el: Use lexical-binding.
(zone): Convert lambda to proper lexical closure.
(zone-replace-char, zone-fill-out-screen): Silence byte-compiler.
* lisp/play/blackbox.el:
* lisp/play/doctor.el:
* lisp/play/gametree.el:
* lisp/play/hanoi.el: Use lexical-binding.
* test/lisp/play/cookie1-resources/cookies:
* test/lisp/play/cookie1-tests.el: New files.
a0451be18b