Linux-PAM for AIX

This patch ports the Linux-PAM library to AIX. The Linux-PAM library is available from:
http://www.kernel.org/pub/linux/libs/pam/
The patch is available from:
ftp://ftp.feep.net/pub/software/PAM/AIX/Linux-PAM-0.75-aix-port.diff
The patch is relative to Linux-PAM 0.75, and I developed it under AIX 4.3.3.

In addition to simple portability fixes, the patch adds a pam_aix module to simulate the traditional AIX authentication behavior. The idea is that the pam_aix module would be used instead of the pam_unix module under AIX. The module supports the following arguments:

auth=type
Use AIX authentication method type. type can be one of the following:
mode=mode
Use mode mode for determining login restrictions. mode can be one of the following:
setpcred
Use AIX setpcred() library function in the pam_setcred() function. setpcred() is not used by default.
Mark D. Roth <roth@feep.net>