Refactor logging configuration

Move logging configuration to lymph.utils.logging and add a new function
setup_logger that can be used by specific drivers and lymph extentions
to setup logging for specific logger instead of having hardcoded logger
configuration in lymph.
It's a matter of where it belong, and since that function is already too weird (manipulating global ...) I think it read better if it all logging related was moved in the logging module instead of being scattered all over the place.