ENG-4633: Preparatory: Pass the interval parameter, if available,
through the non-blocking stats gathering machinery.
ENG-4633: Memory stats are now non-blocking
ENG-4633: IOStats are now non-blocking
ENG-4633: Side-track: Replace multiple occurances of
Cartographer.getPartitions() - 1 to compute the correct partition
count with Cartographer.getPartitionCount() which will do the right
thing.
ENG-4633: Side-track: Delete legacy behavior in
PartitionCountStats.java.  Replace call to
Cartographer.getPartitions().size() which would return a lie with a
call to Cartographer.getPartitionCount()
ENG-4633: "Statistic" PARTITIONCOUNT is now non-blocking
ENG-4633: Side-track: Get rid of stale calls to stats things that were
cluttering my searches.  Clean up various compiler issues in
ExecutionSite by deleting more dead code.
ENG-4633: Initiator stats are now non-blocking.
ENG-4633: Side-track: Grr, the database already checks to see if
you've given it a bad selector.  Stop forcing people to hardwire the
stupid things in SQLCommand as well.
ENG-4633: Side-track: Remove legacy implementation of InitiatorStats.
ENG-4633: Side-track: Delete an old non-IV2 code path.
ENG-4633: Side-track: Clean up an old bad error message.
ENG-4633: Move PARTITIONCOUNT to be non-distributed, like TOPO.
ENG-4633: Cleanup:
- Fix up webstudio's use of PARTITIONCOUNT
- Bring TestSystemProcedureSuite's statistics tests up to date.
ENG-4633: Cleanup: delete unused HashSet
ENG-4633: Add methods to always get aggregated stats without having to
specify site IDs.  Use them in the distributed collectFOOStats()
calls.
ENG-4633: Table stats are now non-blocking
ENG-4633: Index stats are now non-blocking.
ENG-4633: Procedure stats are now non-blocking.
ENG-4633: Starvation stats are now non-blocking.