When `git annex -c foo.bar` runs git-annex transferrer,
it does not pass along the settings from -c.

(Note that, `git -c foo.bar annex` does propagate the -c. Git does it by
setting an environment variable, which causes git config to reflect the
override. The environment variable propagates to child processes.)

There are a lot of config settings that impact transfers,
and some of them might be commonly used at the command line, so something
needs to be done about this. --[[Joey]]

> [[done]]
