ENG-4668: Fix latency stats.  Add test case to TestStatisticsSuite
ENG-4645: DRIVE-BY!  Add a missing length check to the stats returned
by the EE for tables, to match the sane check for indexes.  Add a test
case demonstrating successful database start with an empty schema.
ENG-4606 index compiled statements with constant equality filters
ENG-4167 Fix LeaderElector.start() blocking mode.
Merge master.
Consolidate StatsAgent HSID generation/registration in one place.
StatsAgents are at a well-known site ID, so logging the HSID is not
interesting.
StatsAgent.getMailbox() is a misleading method name, as it returns
void.  Rename.
Merge pull request #504 from VoltDB/eng4668

Eng4668, r=aweisberg for the first commit, not worried about the second
Remove unused argument to populateOverviewTable()
Remove populateDeploymentProperties() dependence on
SystemProcedureExecutionContext.
merge master.
ENG-4668: Make better use of ImmutableList API.  Add a sanity-check
assertion.
live-rejoin-consistency client: report reason if get partition count fails
Merge pull request #506 from VoltDB/ENG-4606-index-on-constants

ENG-4606 index compiled statements with constant equality filters