git-format-patch: add --no-binary to omit binary changes in the patch.

git-format-patch: add --no-binary to omit binary changes in the patch.

Add a new option --no-binary to git-format-patch so that no binary
changes are included in the generated patches, only notices that those
files changed.  This generate patches that cannot be applied, but still
is useful for generating mails for code review purposes.

See also: commit e47f306d4bf964def1a0b29e8f7cea419471dffd, where --binary
option was turned on by default.

Signed-off-by: Caio Marcelo de Oliveira Filho <cmarcelo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>