Fix ONA so that a third level dns domain can add a DNS server.

[daviddpd]

When trying to organize domains into a third level domains, where for example,tn.ixsystems.com 's parent was ixsystems.com - I was unable to add a DNS servers. Further more, the suggestion boxes, would only show util1.ixsystems.com and util1.tn - as seen in the screen shots below. No combination of server and domain would allow the DNS server to be added.

The attached changes, allow this host to be added, and correctly expands util1.tn host name to util1.tn.ixsystems.com. However, the UI gets a little strange, as the server is then "util1.tn.ixsystems.com" and domain being "tn.ixsystems.com" ... it will functionally work as the FQDN in the server, or just the hostname "util1" and the domain "tn.ixsystems.com".