Currently hostwatch only adds hostnames even when FQDNs are available.
This commit changes found_host so that when the name is a FQDN, both the FQDN
and an hostname are added, e.g., given api.foo.com both api and api.foo.com
will be added.

Fixes #151 if merged.

N.B.: I rarely use hostwatch, it would probably be a good idea to get feedback
from people who actually use it before merging. Not too sure about this...