toggling a minor mode should not tell Customize that the value has been set

["Drew Adams" <drew.adams@oracle.com>]

`define-minor-mode' adds this code to the definition of every minor mode:

(if (called-interactively-p)
    (progn
      ,(if globalp `(customize-mark-as-set ',mode)) ; <=== WHY?
      ;; Avoid overwriting a message shown by the body,
      ;; but do overwrite previous messages.
      (unless (and (current-message)
                   (not (equal ,last-message
                               (current-message))))
        (message ,(format "%s %%sabled" pretty-name)
                 (if ,mode "en" "dis")))))

This means that if you so much as toggle a global minor mode, and you later
use `customize-customized' to see which options you have edited and set, the
minor mode variable shows up in the list of customized options.

This is wrong, IMO. Toggling a global minor mode should simply change the
variable's current value; it should not also tell Customize to set that
value (or tell it that the value has been set).

What was the rationale behind this behavior? Why should toggling
`iswitchb-mode' or `icicle-mode' tell Customize that the user has customized
the mode variable?

A user should be able to use `customize-customized' (including perhaps in
`kill-emacs-query-functions') to see what s?he has customized and might want
to save. It is unlikely that a global minor mode variable is in this
category, and if it is, it should only be the use of Customize that counts
for this, not merely toggling the mode.