reduce)
* ftplib.py: added default callback for retrlines; added dir() method
* ftplib.py: don't return self in self.connect(); added hack so that if
  'CDUP' is not understood, 'CWD ..' is tried.
* ftplib.py: second method called init() should have been called
  connect(); if __init__ sees more than one argument, it will also try to
  login().