ISPN-4900 Split-brain: cancelled ST results in missing data

Reset the rebalance confirmation collector when entering degraded mode
ISPN-4934 Upgrade to protostream-2.0.1.Final
ISPN-4925 Enhance documentation on Spring Integration
ISPN-4137 Transaction executed multiple times due to forwarded CommitCommand

Make rollback commands synchronous
Move stuff from AbstraceEnlistmentAdapter to TransactionCoordinator.