Add log level fatal/critical

[CodeCraftTV]

I find myself often missing a Critical/Fatal log level as Error, as of my understanding,may be recoverable and I find it to be easier to comb through logs that say directly where something went unrecoverably wrong. So the hierarchy would look like this:

CRITICAL/FATAL > ERROR > WARNING > INFO > DEBUG > TRACE

What do you think? Would this be useful or am I misunderstanding something?

[Thomasdezeeuw]

Have you seen #334? This has been discussed before, I think it's best to add your use case there.

[CodeCraftTV]

I will ad my use case their. Thx.