Add msg_sep variable to struct diff_options. msg_sep is printed after
commit message. Default is "\n", format-patch sets it to "---\n".
This also removes the second argument from show_log() because all
callers derived it from the first argument:
show_log(rev, rev->loginfo, ...
Signed-off-by: Timo Hirvonen <firstname.lastname@example.org>
Signed-off-by: Junio C Hamano <email@example.com>