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
