code: public Object instantiateValue (String name, String defcname)
          throws Exception
      {
          return Class.forName(getValue(name, defcname)).newInstance();
      }
docs: Looks up the specified string-valued configuration entry, loads the class with that name and
  instantiates a new instance of that class, which is returned.
  
  @param name the name of the property to be fetched.
  @param defcname the class name to use if the property is not specified in the config file.
  
  @exception Exception thrown if any error occurs while loading or instantiating the class.