Merge branch 'jt/format-patch-base-info-above-sig' into maint

"git format-patch --base=..." feature that was recently added showed the base commit information after "-- " e-mail signature line, which turned out to be inconvenient. The base information has been moved above the signature line. * jt/format-patch-base-info-above-sig: format-patch: show base info before email signature