upgrade to last akka version

upgrade akka version to 2.3.4
Merge pull request #3169 from hepin1989/patch-2

upgrade to last akka version
Allow the logging configuration file to be called logback.xml
Merge pull request #3175 from benmccann/logback-xml-2.3.x

Allow the logging configuration file to be called logback.xml
Fixed JNotify load detection

This ensures that dev mode works on FreeBSD.