- Fix issue #1431 (Tx and NoTx used concurrently)
- Review OStorage.callInLock(): add modificationLock call.
- Review OStorage.callInRecordLock(): possible deadlock due to
modificationLock and lock closed in a wrong order.
Merge pull request #1437 from scenari/master

Fix issue #1431 (Tx and NoTx used concurrently)