Merge branch 'jc/test-parse-options-expect'

Merge branch 'jc/test-parse-options-expect'

t0040 had too many unnecessary repetitions in its test data.  Teach
test-parse-options program so that a caller can tell what it
expects in its output, so that these repetitions can be cleaned up.

* jc/test-parse-options-expect:
  t0040: convert a few tests to use test-parse-options --expect
  t0040: remove unused test helpers
  test-parse-options: --expect=<string> option to simplify tests
  test-parse-options: fix output when callback option fails