pack-protocol.txt explains in detail how multi_ack_detailed works and
what's the difference between no multi_ack, multi_ack and
multi_ack_detailed. No need to repeat here.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>