ENG-6033 beef up determinism testing, especially for subqueries, prompting re-implementation.
ENG-6033 add the weaker MP scenarios to determinism tests via cut and paste -- plan to refactor when partitioned subqueries get enabled
Merge branch 'master' into ENG-6033-determinism
TestFixedSQLSuite now less chatty on success and more descriptive on failures
Update PlanAssembler.java
ClientImpl does not properly store the username during initialization so
the HTTP Client looses track of the connection and clients don't get
cleaned up properly.

Also found and fixed an issue where AuthenticatedConnectionCache was not
locking all refcount manipulations.
Merge remote-tracking branch 'origin/master' into ENG-5545-CorrectHTTPClientDeallocation-2
Merge pull request #1224 from VoltDB/ENG-5545-CorrectHTTPClientDeallocation-2

ClientImpl does not properly store the username during initialization so
Update PlanAssembler.java
Merge pull request #1219 from VoltDB/ENG-6033-determinism

Eng 6033 determinism