Update version to 4.0.2.1.
Fix change-version.sh to work on mac and liux.
Move Ubuntu .deb packaging to an Ubuntu machine.
Change some names to be more generic.  Actual machines used are set in 1 place
and otherwise not used.
(cherry picked from commit 9bde88900c021b2fb79bdfe55530439e8933e1f4)
For ENG-5345, also account for bytes released from current write buffer
Merge pull request #1114 from VoltDB/ENG-5345-4

For ENG-5345, also account for bytes released from current write buffer
Merge pull request #1117 from VoltDB/release-4.0.2.x

Release 4.0.2.x