config: Add method to deep-copy a config and validate its contents. Deep-copying will be problematic if non-basic types are in there, so there's a new method to check that this is OK.

{
  "name": "PieCrust",
  "version": "0.0.1",
  "private": "true",
  "dependencies": {
    "bootstrap": "~3.3.2"
  }
}