docs: def getDefaultDict(modname, config_key, loader, reload=False, filename=None):
      """Returns default AIT dictonary for modname
  
      This helper function encapulates the core logic necessary to
      (re)load, cache (via util.ObjectCache), and return the default
      dictionary.  For example, in ait.core.cmd:
  
      def getDefaultDict(reload=False):
          return ait.util.getDefaultDict(__name__, 'cmddict', CmdDict, reload)
      """
      module   = sys.modules[modname]
      default  = getattr(module, 'DefaultDict', None)
  
      if filename is None:
          filename = ait.config.get('%s.filename' % config_key, None)
  
      if filename is not None and (default is None or reload is True):
          try:
              default = ObjectCache(filename, loader).load()
              setattr(module, 'DefaultDict', default)
          except IOError, e:
              msg = 'Could not load default %s "%s": %s'
              log.error(msg, config_key, filename, str(e))
  
      return default or loader()