[WFCORE-148] Make tests more robust
[WFCORE-148] Remove cruft message
[WFCORE-148] Send 400 not 500 if requested stream index is invalid
[WFCORE-148] Add tests of HTTP client use of response streams
[WFCORE-148] Restore methods so legacy test stuff won't fail
Merge pull request #283 from bstansberry/resp-stream-2

[WFCORE-148] Response stream tests and tweaks