The number of characters in a line MUST be no more than 998 characters,
and SHOULD be no more than 78 characters (RFC2822).
It is much safer to fold the header by ourselves.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: Junio C Hamano <junkio@cox.net>