Merge branch 'pw/rebase-m-signoff-fix'

"git rebase --signoff" used to forget that it needs to add a sign-off to the resulting commit when told to continue after a conflict stops its operation. * pw/rebase-m-signoff-fix: rebase -m: fix --signoff with conflicts sequencer: store commit message in private context sequencer: move current fixups to private context sequencer: start removing private fields from public API sequencer: always free "struct replay_opts"