ENG-5707 Python client read buffer performance fix.
ENG-5707 Add Python version check to client.
Merge pull request #1127 from VoltDB/ENG-5707

ENG-5707 Python client read performance fix.
disable long running progress report because it crashes the system
Merge branch 'master' of github.com:VoltDB/voltdb into ENG-451-subquery-xin