* Test out PAM support, extend PAM support by providing environment

 * Test out PAM support, extend PAM support by providing environment
   is specified by /etc/pam.d/init
 * Move utmp/wtmp before the execvp() in spawn() to be sure to
   use the correct pid even on a controlling tty
 * Remaining problem is that the pid of the second fork() for
   getting a controlling tty isn't that reported by spawn()
 * Re-enable writting utmp/wtmp for boot scripts
 * Provide a simply /etc/pam.d/init as without it will not work (sigh!)

git-svn-id: svn://svn.sv.gnu.org/sysvinit/sysvinit/trunk@51 456724a4-4300-0410-8514-c89748c515a2