Added base host only manifest with docker

host.pp added, which assumes the base host
roles for all cases of deployment. This
includes SSH key generation and iptables.

cobbler::iptables calls were modified to
allow the class to be included in two
places in the manifests to meet both
deployment styles.

nailgun::iptables is now called from
nailgun::host class.

Change-Id: Idb016dda6ec64213a7175826de7aae60d3a95158
blueprint fuel-containerization-of-services
Merge "Added base host only manifest with docker"