RelNotes/1.7.7.1: setgid bit patch is about fixing "git init" via Makefile setting

RelNotes/1.7.7.1: setgid bit patch is about fixing "git init" via Makefile setting

The change was actually about "git init -s" which sets the setgid bit on
SysV-style systems to allow shared access to a repository, and can provoke
errors on BSD-style systems, depending on how permissive the filesystem in
use wants to be.

More to the point, the patch was just taking a fix that arrived for
FreeBSD in v1.5.5 days and making it also apply to machines using an
(obscure) GNU userland/FreeBSD kernel mixture.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>