Implement collecting and passing variables into cloud-init

The cloud-init script (stored in the database) is now a template text
using placeholder syntax "%{var}". Variables are colleced both from
OpenStack (nova) and from Chef, then integrated and offered for use in
the cloud-init script.

Now, proper hostname can be passed to both OpenStack and Chef as the
node name, and instantiated nodes from within a Deployed Package can
reference each other's data (e.g. the web server can now find its
database server).