Context based log filtering with log4j-1.2.x

Even though the current logging configuration in archetype is designed to keep context-based separate log files (e.g, hippo-cms.log for cms/repo application and hippo-site.log for site application), the current solution doesn't seem to provide the designed feature property.
For example, if you use hippo-repository-connector classes in an HST component, then you will see the logs generated by the
hippo-repository-connector classes in the hippo-cms.log file, not in the hippo-site.log file because default configuration for log4j is not so flexible and so it is strictly tied to the class/package names only.

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We can do the following with log4j:

• Add a simple MDC or JNDI based Filter in a hippo shared lib (See
  'Log4JMDCFilter' example in [1] for detail).
  (hippo-cms7-commons-x.x.x.jar)
• I think JNDI based resource configuration should be better because it's safer in a separate thread as well.
• Set JNDI resource property in each web.xml
• Configure 'conditional logging' in the existing log4j.xml.