As outlined by Jean-Francois add a createConfiguration method that detects AnnotationConfiguration on the classpath:

try
 {
    // Try to instantiate AnnotationConfiguration by reflection
   Class clazz = Class.forName( "org.hibernate.cfg.AnnotationConfiguration");
   Configuration config = (Configuration) clazz.newInstance();
   return config;
}
catch (Exception e)
{
    // Fall back to normal configuration
    return new Configuration();
}