new config option "fetch.all"

[Tamino Bauknecht <dev@tb6.eu>]

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