* tutorial.el: Remove `cl' requirement. Clean up whitespace.

* tutorial.el: Remove `cl' requirement.  Clean up whitespace.
	Replace '?\ ' by '?\s' throughout.
	(tutorial-warning-face): Inherit font-lock-warning-face.  Move to
	`help' custom group.
	(tutorial--key-description): New function.
	(tutorial--display-changes): Remove redundant arg.  Scan for all
	key sequences to avoid false matches.  Cleanup.
	(tutorial--saved-dir): Save to a subdirectory in .emacs.d to
	reduce homedir pollution.
	(help-with-tutorial): Call tutorial--display-changes with no arg.