Re: highlight-changes-mode

[Richard Stallman]

    highlight-changes-mode in mode-line-mode-menu doesn't toggle on the 
mode-line
    because it has three values:

      With an argument ARG:
        If ARG is positive, set state to active;
        If ARG is zero, set state to passive;
        If ARG is negative, disable Highlight Changes mode completely.

I think we should change the interface, because it is really bad for a
minor mode to be inconsistent with the standard for minor modes.