Re: tooltip custom group: duplicate labels

[Richard M. Stallman]

    I suggest removing their tags to show unambiguous labels that have the
    word "tooltip".

I see no reason to keep any of the tags in gud.el.  Let's just delete
them.

    Perhaps there should be some generic solution, e.g. using a heuristic
    to place an option with the substring "-mode" before other options in
    the customization buffer or something like this.

That might be a good idea; I will add it to etc/TODO.