Fluent interface

I'm starting to sway towards the idea of having a fluent interface. I didn't deem it necessary at first, but with `Context#configure` and a few of the new things I'd like to add, a FI seems to make sense.

Something like:

```js
context.wire(Foo)
  .asSingleton('foo')
  .withWiring({
    baz: 'qux'
  })
  .withContextEvents({
    "system:somethingHappened": "doBar"
  });
```

The thing is, I notice I'm pulling more and more of the Geppetto stuff out of the ordinary actors and into the wiring phase, which means you need more possibilities, which in turn means you want to apply more methods to the same wiring configurations.

@geekdave what do you think?