completely rewrote the AIX UESS backend (UESS is the AIX equivalent of

completely rewrote the AIX UESS backend (UESS is the AIX equivalent of
NSS). This time I think I've actually got it right. I wrote a fairly
good test suite for UESS modules (similar to nsstest.c) that allowed
me to explore how the modules supplied with AIX actually work.

This new module also incorporates authentication features, so you
don't need a PAM module at all. Just install this UESS module and
authentication will "just work". It also handles password change, so
/usr/bin/passwd can be used to change windows password.
(This used to be commit d62cb9454e310d2baeea0077dad4ba9382ba06cd)