        Provides a `git rebase` rerere auto continue function.  It may be
        used as a drop-in replacement front-end for `git rebase -m` that
        automatically continues the rebase when `git rerere` information is
        sufficient to resolve all conflicts.

        You have enabled `git rerere` haven't you?

        If the `-m` or `--merge` option is not present then `tg rebase`
        will complain and not do anything.

        When `git rerere` is enabled, previously resolved conflicts are
        remembered and can be automatically staged (see `rerere.autoUpdate`).

        However, even with auto staging, `git rebase` still stops and
        requires an explicit `git rebase --continue` to keep going.

        In the case where `git rebase -m` is being used to flatten history
        (such as after a `tg export --collapse` prior to a
        `git format-patch`), there's a good chance all conflicts have already
        been resolved during normal merge maintenance operations so there's no
        reason `git rebase` could not automatically continue, but there's no
        option to make it do so.

        The `tg rebase` command provides a `git rebase --auto-continue`
        function.

        All the same rebase options can be used (they are simply passed through
        to Git unchanged).  However, the `rerere.autoUpdate` option is
        automatically temporarily enabled while running `git rebase` and
        should `git rebase` stop, asking one to resolve and continue, but all
        conflicts have already been resolved and staged using rerere
        information, then `git rebase --continue` will be automatically run.

