akka/akka — pull request #408 by rkuhn (2012-04-23 13:42:16+00:00)
Title: add option to log UnhandledMessage, see #1999

- LoggingBus.startDefaultLoggers will register a forwarder actor for
UnhandledMessage, which republishes them as Debug message
- add tests and docs
- TestEventListener logs UnhandledMessage as Warning