Merge branch 'kn/reflog-migration'

"git refs migrate" learned to also migrate the reflog data across backends. * kn/reflog-migration: refs: mark invalid refname message for translation refs: add support for migrating reflogs refs: allow multiple reflog entries for the same refname refs: introduce the `ref_transaction_update_reflog` function refs: add `committer_info` to `ref_transaction_add_update()` refs: extract out refname verification in transactions refs/files: add count field to ref_lock refs: add `index` field to `struct ref_udpate` refs: include committer info in `ref_update` struct