Allow dynamic runtime switching of source files
Allow subclasses of DocumentLoaderImpl to change how cache keys are generated, thus allowing multiple source files to be used with the same interface and implementation class.
See email list thread: http://www.objectweb.org/wws/arc/xmlc/2007-01/msg00000.html
Check out the attached demo app that demonstrates this new feature. Read the README for instructions on how to build and run the app.