Production now uses CDH (CDH5) module, also refactor roles

This prepares the Hadoop cluster for reinstallation with CDH5.
Roles have been refactored so that the realm specific
classes are removed.  There are now a standalone ::config class
that can be included in order to use configs in other
manifests without installing and configuring CDH packages.

Change-Id: Icafcf8b5683d892209563f616d8fa7544028a3c3