This change is a reworking of the way that messages are sent to clients from the service layer. It is also a reworking of the protocol to ensure that all formulations of query send back events to the client in a deterministic ordering. To support the first change:
* Added a new event that will be sent when a message is generated
* Messages now indicate which Batch (if any) generated them
* Messages now indicate if they were error level
* Removed message storage in Batch objects and BatchSummary objects
* Batch objects no longer have error state
* added support for timestamps
* fixed tests
* Moved message class to own file; added 'z' to end of date strings
* added default time constructor
* removed unnecessary z
* added time string format info in comment
* changed from utc time to using local time