replace log4j with nlog4j

Would be nice, if you would switch over to nlog4j, since than people can start using slf4j and do not need to have a separate classloader for each app/service. Since nlog4j is compatible to log4j, it would require no code changes but leaves the door wide open (even for the jboss logger ...).

As proof of concept I copied nlog4j.jar over thirdparty/apache-log4j/lib/log4j.jar and made a minor build.xml adjustment for the log4j-boot.jar (see attached patch) and rebuild jboss. Works without any problems