Keytab scripts should ensure that all hostnames are in Kerberos keytab

[billglick]

There are times where we need multiple hostnames for a host and have those all in the Kerberos keytab.

For instance GSSAPI authentication into a host that has multiple hostnames for different network interfaces require the KDCs and the local keytab file to have host principals for each hostname.

It would be nice to be able manage the creation, renewal, and cleaning of multiple/all host principals on a host.