ticket 1705 - internationalize help topics
    
    * Wrap each topic description in _()
    
    * Replace the use of if 'topic' in dir(module) with the more
      Pythonic and efficient getattr(module, 'topic', None)
    
    * Make sure to invoke unicode on the value returned from _()
      otherwise you'll get a GettextFactory instance, not a string
    
    * Clean up trailing whitespace errors