Added exceptionCaught override to MessageHandler, will log the exception
as a WARN
 - Also set log4j to INFO, there's nothing showing in the console
otherwise!
 - Changed the log format to put the thread info after the log level
RFID Number in current message is optional, changed CurrentWorkflow to
handle the case where there's no rfid number in the message
- Changed the dump to set RFID_TAG_ID to DEFAULT NULL
- Added test case
- Updated client to sometimes omit the rfid number