[PATCH] add possibility to use git in a sub-folder for multi repo

[Jason A. Donenfeld]

Hi Philippe,

I like this idea, but the implementation is bad. Please use getopt
just like every other subcommand that takes arguments. When you
resubmit, please send this using git-send-email, with the patch inline
like usual, so that I can actually review the patch. Failing this, it
won't be reviewed or accepted.

Jason