[Cooker] su && pam problems fix

[Bryan Paxton]

The problem is with the lasest sh-utils the su module in /etc/pam.d is 
looking for /etc/pam.d/system-auth, which isn't there(not part of the lasest 
pam rpm). Just add a few lines to pam.spec to remedy 
this(pam-%{version}/system-auth.pamd).

Blaaaaaaaaaaaaaaa : )
-- 
Bryan Paxton
Public key can be found at http://speedbros.org/bryan.paxton.asc