Merge branch 'rr/revert-cherry-pick'

* rr/revert-cherry-pick: t3502, t3510: clarify cherry-pick -m failure t3510 (cherry-pick-sequencer): use exit status revert: simplify getting commit subject in format_todo() revert: tolerate extra spaces, tabs in insn sheet revert: make commit subjects in insn sheet optional revert: free msg in format_todo()