ENG-5434 added VEM core support for KSafety and Rebalance stats
merge from master. resolved conflicts in LeaderAppointer, and KSafetyStats
Merge branch 'master' into ENG-5434
Merge branch 'master' into ENG-5434
ENG-5434 better VEM join support
Merge branch 'master' into ENG-5434
ENG-5434 addressed Andrew G. UI Comments
ENG-5434 addressed Ning's code review comments
Merge pull request #1010 from VoltDB/ENG-5434

ENG-5434 better VEM support for elastic join