resolv.conf search path doesn't match the domain for the host

When a machine is deployed, we appear to always give it a search path based on the default domain, rather than the actual domain that the machine is in. As a result, the machine cannot resolve its own hostname (since it becomes $MACHINE_NAME.$DEFUALT_DOMAIN} instead of the actual node.fqdn.

To reproduce (given default domain of "maas"):
1. add a domain "bad"
2. Deploy a machine as "testhost.bad"
3. Login and note thus:
     hostname -f
     hostname: Name or service not known
4. Note also that /etc/resolv.conf has "search maas" instead of "search bad" or "search bad maas"

The short fix is probably to make it say "search bad", with a long-term solution of allowing the search list for the node to be specified by the admin (and always prepending node.domain.name, since that determines the FQDN for the host.)