ENG-6857: Initial defaultprocread for Jenkin.
ENG-6857: add catalog update to change group with flipping defaultprocread.
ENG-6857: refactor out decision making in one place.
ENG-6857: review changes.
ENG-6857: refactore more...
Merge pull request #1709 from VoltDB/ENG-6857

Eng 6857