Re: parse-options does not recognize "unspecified" behavior

> The goal comes from his GSoC microproject. Specifically, Pranit wants
> an "unspecified" value. The reason is that he is adding a
> commit.verbose=<level> config variable to back the existing git-commit
> --verbose option. Any use of --verbose (one or more times) or
> --no-verbose should override the config.verbose value altogether, so
> he wants a way to know if --verbose or --no-verbose was used; hence
> the "unspecified" value. And, really, this issue isn't necessarily
> specific to git-commit. It could apply to any command that understands
> verbosity levels and wants to be able to get them from both a config
> variable and a command-line option.
>
> A much easier solution would be to update OPT_VERBOSE() to understand
> that negative values are "unspecified", and then --verbose would
> (pseudocode):
>
>     if (value < 0)
>         value = 0
>     value++;
>
> and --no-verbose would:
>
>     value = 0
>
> That should be compatible with existing clients of OPT__VERBOSE()
> which initialize the value to 0, and should satisfy Pranit's case; he
> can initialize it to -1, and if it is still -1 when option parsing is
> done, then he knows that neither --verbose nor --no-verbose was seen.