We're switching Atom to React, but we want to support backward-compatible shims to our previous view framework.

In the old framework, views were represented as jQuery-wrapped DOM elements. Ideally, we'd like to provide backward-compatible shims by simply rendering the React component and wrapping its root element in a jQuery wrapper with an API that's compatible to our old editor views. That would essentially look like this:

``` javascript
var editorRoot = document.createElement('div')
React.renderComponentWithRootElement(Editor(props), editorRoot)

// the element would actually be wrapped in a custom subclass of jQuery,
// but this is clearer for this example
var editorShim = $(editorRoot) 
```

Currently, this isn't possible because React components need to be rendered into a container. So instead we need to create a wrapper element and render the component inside it. This is sad because it adds an extra layer of markup which confuses styling, and also means that the editor has a wrapper when used via the shim layer but no wrapper when embedded as a child via React itself.

Is there something fundamental preventing React from adopting DOM nodes directly without the parent? Is this something we could even hack in in a way that would be somewhat maintainable?

:heart:

this._enqueueCallback(callback, publicInstance);
    this._renderer._newState = completeState;
    this._renderer.render(this._renderer._element, this._renderer._context);
  }
  enqueueSetState(publicInstance, partialState, callback, callerName) {
    this._enqueueCallback(callback, publicInstance);
    const currentState = this._renderer._newState || publicInstance.state;
    if (typeof partialState === 'function') {
      partialState = partialState.call(
        publicInstance,
        currentState,
        publicInstance.props,
      );
    }
    
    if (partialState === null || partialState === undefined) {
      return;
    }
    this._renderer._newState = {
      ...currentState,
      ...partialState,
    };
    this._renderer.render(this._renderer._element, this._renderer._context);
  }
}
function createHook(): Hook {