No fatal log level

[molynerd]

We used to have this log level in the C# version of the logger (using log4net) and when using the winston transport for nodejs. This seems to be missing here and is critical for our environment.

If acceptable. I'd like to get this feature added.

[molynerd]

went ahead and PR'd it. let me know your thoughts.

[darinhoward]

@molynerd I'll review - should be able to merge and publish tomorrow. Thanks for the pull request.