gh-935

**not ready for merge**

Right now this takes care of generating the right output format - consuming it is another matter
So we not only need to put the 'parsed' back on the same instance, but in the right place. Example would probably help:

```js
var C1 = Ractive.extend({
 partials: { foo: 'foopartial' } }
})
var C2 = C1.extend({})
var Widget = Ractive.extend({
  template: '{{>foo}}'
})

var c2 = new C2({
   el: 'body',
   template: '<widget/>',
   components: {
      widget: Widget
  }
})
```
So when `widget` needs the foo partial, it looks up the view hierarchy and finds it on the `c2` instance. The first time, it won't be parsed, so it gets parsed. But the parsed partial needs to be assigned to `C1.partials.foo` (actual via the parallel `c2.partials` registry inherited object, but points to the same thing).

Does that make sense?