[plug] sync passwd and smbpasswd passwords

[Chris Watt]

Tried for months to make it a PDC.  I'm not going there again no
matter what anyone says unless they want to come down here and do it
themselves.

All I want to do is make it so when the unix password is changed, the
samba password is changed as well.

Ideally I'd've liked a single sign on system but I just do not have
the time anymore adn the whole project is as a charity to a charity.

Thanks
~Chris