ticket #673 - log4j still works, juli still works but can now switch to logback.xml

I left comments in the ticket  http://play.lighthouseapp.com/projects/57987/tickets/673-feature-request-use-logbackslf4j-instead-of-log4j

note that current playframework has a bug in logging ordering on a single thread.  Anyone that switches tot his logback version solves that issue(that issue should be solved in a separate ticket eventually).

thanks,
Dean