octopus: make merge process simpler to follow Its not very easy to understand what heads are being merged given the current output of an octopus merge. Fix this by replacing the sha1 with the (usually) better description in GITHEAD_<SHA1>. Suggested-by: Jari Aalto <jari.aalto@cante.net> Signed-off-by: Stephen Boyd <bebarino@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>