Log level settings should accept strings (eg "INFO")

[therefromhere]

For consistency with Python's logging config (and to avoid having to import logging into settings), we should probably allow the REQUEST_LOGGING_DATA_LOG_LEVEL and REQUEST_LOGGING_HTTP_4XX_LOG_LEVEL settings to be set as strings ("INFO" etc) as well as the enum values from logging (logging.INFO etc).

[joeyworld]

Can I also write my opinion?

This seems related with #47 since it introduces with new settings.
I'm actually positive with introducing a set of project-level settings, as long as well-written documentation is provided!

[tclancy]

I don't really see a crossover as #47 doesn't seem to need a setting, but I am ok in general with the idea of making a package-level settings like Django Rest Framework or Debug Toolbar rather than a series of individual REQUEST_LOGGER_X settings if that's what you mean. OTOH, backwards compatibility would be a concern.