bug#18992: 24.4; describe-mode

[Drew Adams]

> Well, but of course having the mode functions printed in `describe-
> mode' wouldn't hurt anyway.  This patch does that:

This is an improvement.

> However, in contrast to major-modes, minor mode names tend to be
> much longer, so we can get some long lines like:
> 
> Global-Edit-Server-Edit minor mode (`global-edit-server-edit-mode';
> no indicator):

Yes, that violates *Help* conventions.  It is better to use this
(or similar):

;; Document the minor modes fully.
(insert pretty-minor-mode)
(princ (format " minor mode:\n(`%s'; %s)\n"
       mode-function
       (if (zerop (length indicator))
           "no indicator"
         (format "indicator%s" indicator))))
(save-excursion
  (fill-region-as-paragraph
    (line-beginning-position 0) (line-end-position 0) nil t t))