Merge branch 'kh/replay-invalid-onto-advance'

Improve the error message when a bad argument is given to the `--onto` option of "git replay". Test coverage of "git replay" has been improved. * kh/replay-invalid-onto-advance: t3650: add more regression tests for failure conditions replay: die if we cannot parse object replay: improve code comment and die message replay: die descriptively when invalid commit-ish is given replay: find *onto only after testing for ref name replay: remove dead code and rearrange