Adding logging/error-reporting system

Discuss here -- should the logging/error-reporting system be exposed through the API?

What would this mean in practice?

I think the library user should be able to set the log level. This should be exposed by the API.

jml::global_log_level(DEBUG);

Should the library users be able to call the logger itself? Probably not. We probably don't need to allow the following.

jml::log(DEBUG, "This is a debug message");

Would the user need or want to access the data of the logs for any reason? Like programmatically check if any warnings have been created?

jabacat / jml