Extract logging from environment.xml

It has been suggested that we should extract logging definition from environment.xml and place it in a new file

SAR-INF/log.xml

This has been suggested because it mimics behaviour in other containers and logging can not really be considered to be part of the "environment" of an application.

Further details are available in message

http://marc.theaimsgroup.com/?l=avalon-dev&m=104651163517039&w=2

Which contained:

Ages ago (a year or two?) we decided that we wanted to separate out logging configuration from environment.xml - is this still desired? The reason is that I am currently documenting this and want to finalize the implementation prior to doccing it.

The idea was to do something like

SAR-INF/assembly.xml
SAR-INF/config.xml
SAR-INF/environment.xml
SAR-INF/logging.xml

and SAR-INF/logging.xml contains all the configuration for logging. I think it is just a case of no one getting around to doing it. This was just after Giacomo wrote the excalibur-logger package and we wanted to harmonize between Cocoon and Phoenix in this aspect.

However I now have another motivation to do this. Several people have asked for support for log4j or native JDK1.4 logging configuration formats. So if we went the above way we could separate out logging we could search for configurations in the following order;

SAR-INF/environment.xml (for backwards compatability)
SAR-INF/logging.xml (excalibur logger)
SAR-INF/log4j.xml (log4j xml format)
SAR-INF/log4j.properties (log4j properties format)
SAR-INF/log.properties (JDK1.4 format)

That way people who want to use Log4j config files can do it easily.