bug#59414: 29.0.50; Have vc-git-expanded-log-entry pass --stat

[Juri Linkov]

> - vc-git-print-log -- should choose which defcustom to include based on
>                       its SHORTLOG parameter
> - vc-git-log-outgoing -- vc-git-shortlog-switches
> - vc-git-log-incoming -- vc-git-shortlog-switches
> - vc-git-log-search -- vc-git-log-switches
> - vc-git-expanded-log-entry -- vc-git-log-switches
>
> This is because some options are incompatible with shortlogs, such as
> --stat.  So, the proposed change is to add the new defcustom, change
> vc-git-print-log to use both defcustoms, and change all the other
> functions to use one of them.  How does    this sound?

Your classification correctly reflects the current situation
where two types of logs are in use by these commands.  So I think
two defcustoms as the minimal number of customization knobs
is a good idea.