Available Severity levels

1. Notice - Just a general notice.
2. Debug - A debug message - There shouldnt be too many of these.
3. Warning - A warning that the program state is not quite as expected and something may go wrong later because of it.
4. Error - Something has gone wrong but recovery may be possbile. The program will attempt to continue but a Failure may later occur.
5. Failure - An unrecoverable error has occured. This message should probably include a stack trace and any program state information. After issuing one of these the program should try to terminate nicely.