Add option to install imaging and load balancing services

A much simplified patch that calls the chef recipes that already do this. Tested against a vanilla CentOS install and works in both the "yes install extra services" case and the "no don't install extra services" case.  

The ciab-template.json file is changed to represent that there's now the ability to choose the extra services. Previously, these were just set to false.

The cloud-in-a-box.sh changes are also quite minimal; they just ask the user if they want to add the services and set variables accordingly, including telling the user about the additional time that will be required in these cases.