Added another authentication interface to winbindd. The Challenge Response

Added another authentication interface to winbindd.  The Challenge Response
Authentication Protocol (CRAP) takes a tuple of (username, random
challenge, encrypted lm password, encrypted nt password) where the
passwords are encrypted with the random challenge ala ntlmssp.
(This used to be commit 11f72a78e3a16bbb17b576d80b47a9eb818ee428)