new config option "fetch.all"

Hi all,

when working on repositories with different remotes, I find myself using "git fetch --all" quite often. Thus, I thought that git might benefit from having a config option "fetch.all" which will allow to always fetch all available remotes if enabled (either in global or repository config).

The same already exists for "fetch.prune" and I don't really see any downside to providing that convenience option also for "--all". A probably necessary adjustment is that if the config is enabled and a repository is explicitly specified, the specified repository should be used instead of "--all". Otherwise, the current output would be: "fatal: fetch --all does not take a repository argument".

If no one sees any further issues, I'll gladly work on this feature and provide a patch.

Best regards, Tamino Bauknecht