Fix commentary section. Don't require cl for compilation.

Fix commentary section.  Don't require cl for compilation.
(generic-mode-list): Add autoload cookie.
(generic-use-find-file-hook, generic-lines-to-scan)
(generic-find-file-regexp, generic-ignore-files-regexp)
(generic-mode, generic-mode-find-file-hook)
(generic-mode-ini-file-find-file-hook): Fix docstrings.
(define-generic-mode): Make it a defmacro.  Fix docstring.
(generic-mode-internal): Code cleanup.  Add autoload cookie.
(generic-mode-set-comments): Code cleanup.