ENG-5711: WIP code to run mixed versions of VoltDB in a cluster.
Merge branch 'ENG-5712' into ENG-5799
Merge remote-tracking branch 'origin/ENG-5712' into ENG-5711
ENG-5799 clean up volt compiler error messages.
Merge remote-tracking branch 'origin/master' into ENG-5711
ENG-5799 Got rid of a pointless error message.
ENG-5711: Make Hotfix work. Seems to now.
Added tests.
Merge remote-tracking branch 'origin/master' into ENG-5711

Conflicts:
	src/frontend/org/voltdb/compiler/DDLCompiler.java
ENG-5711: Make sure we can run with version strings that have alpha in them.
Merge remote-tracking branch 'origin/ENG-5712' into ENG-5711
Merge remote-tracking branch 'origin/ENG-5712' into ENG-5711

Conflicts:
	src/frontend/org/voltdb/utils/CatalogUtil.java
	tests/frontend/org/voltdb/utils/TestCatalogUtil.java
Merge remote-tracking branch 'origin/master' into ENG-5711
ENG-5711: Self-reviewed cleanup.
Merge remote-tracking branch 'origin/master' into ENG-5711
ENG-5711: Taking review feedback.
ENG-5711: Taking scooper's feedback.
ENG-5711: Fix test bug.
ENG-5711: Fix broken regex.
ENG-5711: Fix EE loader versioning bugfix bug.
ENG-5711: Localcluster minor fix.