Merge branch 'ab/sequencer-unleak'

Plug leaks in sequencer subsystem and its users.

* ab/sequencer-unleak:
  commit.c: free() revs.commit in get_fork_point()
  builtin/rebase.c: free() "options.strategy_opts"
  sequencer.c: always free() the "msgbuf" in do_pick_commit()
  builtin/rebase.c: fix "options.onto_name" leak
  builtin/revert.c: move free-ing of "revs" to replay_opts_release()
  sequencer API users: fix get_replay_opts() leaks
  sequencer.c: split up sequencer_remove_state()
  rebase: use "cleanup" pattern in do_interactive_rebase()