'git log --graph --oneline --decorate --all' is a useful way to get a
general overview of the repository state, similar to 'gitk --all'.
Let it indicate the position of HEAD by loading that ref too, so that
the --decorate code can see it.
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>