The negated forms introduced in c426003 (format-patch: add --no-cc,
--no-to, and --no-add-headers, 2010-03-07) were not documented
anywhere. Add them to the descriptions of the positive forms.
Signed-off-by: Thomas Rast <trast@student.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>