(finder-headmark): Initialize and add doc string.

(finder-headmark): Initialize and add doc string.
(generated-finder-keywords-file): Doc fix.
(finder-no-scan-regexp): New variable.
(finder-compile-keywords): Use a single let binding.  Disable undo in
the output buffer.  Use autoload-rubric.  Use mapc rather than mapcar.
Don't scan files matching finder-no-scan-regexp.  Use
with-temp-buffer.  Use expand-file-name rather than concat.  Use
directory-files to do regexp matching.  No need to require jka-compr.
(finder-list-keywords): Remove un-needed set-buffer.  Disable undo.
(finder-list-matches): Disable undo.
(finder-commentary): Use let rather than let*.  Disable undo.
(finder-current-item): Use zerop.
(finder-mode): Use define-derived-mode.
(finder-exit): Doc fix.  Use dolist.