allow Logging Serializable classes to be deserialized

Found this library today, love it, moved tons of files over to it (from log4j) already.

The one issue I've found is that marking a Serializable class as Logging makes it unserializable - or un-deserializable, rather.

It seems that just marking the logger field as transient allows the class to be deserialized properly, and of course the field is recreated on the deserialized object.