The behavior of "git push --force" is rather clear when it updates only
one remote ref, but running it when pushing several branches can really
be dangerous. Warn the users a bit more and give them the alternative to
push only one branch.
Signed-off-by: NMatthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>