Consider separating monolithic config into separate configs, allowing `nodebuilder.Store` to move to `nodebuilder/node.Store`

[renaynay]

Move nodebuilder.Store to nodebuilder/node

• There is a dependency cycle with it, and the cycle just reveals the symptom of another problem - monolithic Config
• The Store has to be changed to allow storing Configs independently

Config(module string) (interface, error)
PutConfig(module string. interface) (error)

In both cases, the Config access can go either to the same file or different. depends on the implementation of the Store