Add support for temp table count star optimization
Get rid of the extra flag, use the subquery flag instead; Add test cases for temp table count query optimization;
Use Paul's way to clean up the executor
Merge branch 'master' of github.com:VoltDB/voltdb into ENG-6359-temptable-count
Merge pull request #1388 from VoltDB/ENG-6359-temptable-count

Eng 6359 temptable count