please add log4j2 config to a sample project #1442

It seems log4j was upgraded to log4j2 in #1367 for play 1.7.0

So any application using oldstyle log4j.properties will/did now stop producing logfiles.
It is not clear from docu or anywhere else how to configure log4j2.
Adding a basic log4j2.xml in conf/ folder had no effect.
Maybe a change in application.conf is required? Or adding a dependency.yml entry?

May I ask you to please add a most basic working log4j2 setup to any of the projects under samples-and-tests ?