This points readers at the "Recovering from upstream rebase" warning
in git-rebase(1) when we talk about rewriting published history in the
'reset', 'commit --amend', and 'filter-branch' documentation.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>