ISPN-4565 ReplTotalOrderVersionedStateTransferTest.testStateTransfer ran...

...dom failures

* fix NPE:CommitCommand should not trigger the PrepareCommand.
* fix timeout: CacheTopologyControlCommand should be processed in the deliver thread

https://issues.jboss.org/browse/ISPN-4565
Yeah, but we don't block txs during state transfer without TO...