Debian jessie introduced pam-auth-update, which packages call when they have
bits of common PAM configuration.

Add two new parameters. The first is to add a line to the krb5.conf file
indicating that we prefer TCP. The other is a parameter stating which
kerberos environment we want: prod, test, or uat.

If the system's primary IP address is in one of the two well-known Livermore
netblocks, then automatically set the Livermore-based Kerberos server as the
primary KDC.

base::kerberos::dr is now deprecated.

We know the three large IP address blocks that exist in Livermore, and we now
have an ip_in_cidr() function, so we are using that to tell if a system is in
Livermore.

This code will need updating only if the large network blocks in Livermore are
changed.

We don't have anycast DNS in Livermore, so this adds a parameter to base::dns,
a parameter that can be set via Hiera, to put Livermore's DNS server at (or
near) the top of the list.

This is important for systems using Puppet and DHCP, because DHCP renewals
rewrite resolv.conf, which then gets re-re-written by Puppet.