For ENG-5927, don't log in client when subscribe procedure isn't found in pre 4.1 clusters
For ENG-5927, add missing return
ENG-5916: Command log replay end of log handling changes.

Simplified ReplaySequencer by removing EOL message for each partition, only the
MPI sends EOL message to SPIs now, which indicates EOL of all partitions.

Add poison flag to MpReplayAckMessage to indicate MPs with missing
sentinels.
Merge pull request #1157 from VoltDB/ENG-5916

ENG-5916: Command log replay end of log handling changes.
Merge pull request #1158 from VoltDB/ENG-5927

Eng 5927
For ENG-5803, add support for disabling compaction
Merge branch 'master' into ENG-5875-ee-characters
Fix a correctness issue with disabling async logging and fix a potential performance issue with disabled log levels still generating tasks for the log thread
Fix typo in previous commit for log4j async improvements
Merge pull request #1161 from VoltDB/log4j_async_check

Log4j async check, don't create a task of the log level isn't set
Merge branch 'master' into ENG-5875-ee-characters
Merge pull request #1164 from VoltDB/ENG-5803

For ENG-5803, add support for disabling compaction
Update doc PDFs.
One minor addition to the UsingVoltDB.pdf
ENG-5941 Fix recovery breakage due to new catalog version check.
Merge branch 'master' of github.com:VoltDB/voltdb
ENG-5878: Print an error message if a system has older python than 2.6.
ENG-5947 ENG-5948 Misc. catalog upgrade fixes/tweaks.
Merge branch 'master' of github.com:VoltDB/voltdb
Merge branch 'master' into ENG-5875-ee-characters