If the client requests the side-band-64k protocol capability we
now wrap the status report data inside of packets sent to band #1.
This permits us to later send additional progress or informational
messages down band #2.
If side-band-64k was enabled, we always send a final flush packet
to let the client know we are done transmitting.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>