The new help option --config-for-completion is a machine friendlier
version of --config where all the placeholders and wildcards are
dropped, leaving only the good, completable prefixes for
git-completion.bash to consume.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>