Make sure the response has been written before the latch is released
Minor graceful shutdown improvements
Merge pull request #288 from stuartwdouglas/WFCORE-177

WFCORE-177 fix intermittent failure in suspend test case
[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