Changed pam_script to handle chroot, unshare and mount.

Hi,

I've rewritten an existing pam module pam_script. What it does:

. runs a script
. unshare the mount namespace (if configured, default yes)

if the directory to chroot to is specfied it does also:

. mount all the required directories like bin, lib, usr etcetera.
. chroot to this directory

See:

git clone git://gitorious.org/pam_script/pam_script.git pam_script
cd pam_script


Please some comments.

Stef