ADD: "pyFtp": Add warning about pending commands being canceled on errors.
FIX: "pyFtpCallback.__del__()": Fix wrong reference to "self.callbacks".
ADD: "pyFtpCallback.handleSignal()": Check callback before trying to call it.
FIX: "pyFtp.commandFinished()": Remove open file resource after closing.
FIX: Work around Qt bug preventing timeout errors during connection.