Fix logging setup _ Silence message about missing SLF4J implementation _ Route java.util.logging to Log4J (at least restlet is affected) _ Let messages of additional loggers pass to the root loggers appender (otherwise, they don't appear at all)

<?xml version="1.0" encoding="UTF-8" ?>
<rest-server>
    <!--  The port which the ArtifactDatabase (ArtifactServer) will bind to. -->
    <port>8181</port>
    <listen>0.0.0.0</listen>
</rest-server>