ISPN-2366 Rename state transfer config option 'waitForInitialStateTransferToComplete' to 'awaitInitialTransfer'

* The previous name was not choosen well.

* Revised javadoc and XSD documentation for this config option to higlight the consequences of turning it off.
ISPN-2578 Two PrepareCommands in parallel cause ConcurrentModificationException
ISPN-2728 AbstractCacheTransaction.hasLockOrIsLockBackup may cause NPE
- temporary fix