Support for upgrading from 1.9 and 2.0

- added support for reading 1.9 and 2.0 log files
- fix: PhysicalLogNeoCommandReaderV0 should parse 1.9 commands
I think it'd be better if we had two separate PhysicalNeoCommandReaderV0, one for 19 and one for 20, perhaps subclassing the same base abstract class and providing version specific reader implementations for the records that need it