Server/persistence/command

## changes

- each of the three objects now have a `getBytes()` method so that they can be stored as blobs (or to do file serialization)
- the command access class should now be complete
- the command creator should now be complete
- there is a database creator abstract class that will do the `initializeMany()`
- check out the DataUtils class for object **deserialization** (deserializing blobs)