Adds the enterprise service to the agent's boot process. A few
placeholders have been added because it's not quite clear how we should
generate ProductIDs and ClusterIDs for Telegraf
This will basically make the root directory a place for storing the
major telegraf interfaces, which will make telegraf's godoc looks quite
a bit nicer. And make it easier for contributors to lookup the few data
types that they actually care about.
closes#564