r15038: Replace all code in pam_winbind that relied on access to samba

r15038: Replace all code in pam_winbind that relied on access to samba
internals, mostly with the code that was in pam_winbind before.

Also switch from using loadparm to use iniParser to read the new
pam_winbind options from a configuration file. That still uses the old
(parametric) option names which will be replaced next (as iniParser does
not support parametric options).

Guenther