Remove methods which expose internal ID

Remove the following methods which expose internal IDs
from public view:

- DatastoreExtended#getDocNumericId() - Removed from public interface
- BasicDocumentRevision#getInternalNumericId() - Changed visibiity to protected
Remove getAllRevisionsOfDocument(long docNumericID)

Remove BasicDatastore#getAllRevisionsOfDocument(long docNumericID)
method and move its funtionality to
 BasicDatastore#getAllRevisionsOfDocument(String documentId)