Support inline compilation errors

The `LiveError` component is useful for displaying compilation errors. But the `LiveEditor` component could be even more useful if it showed inline errors. For example:

### Current UI

### Potential UI

This support could probably be added in such a way that is not dependent on a specific compiler/toolchain. For example, `LiveEditor` could expose an additional prop `errors` that looked something like this:

```js
type errors = Array<{
message: string,
rowNumber: number,
columnNumber?: number
}>
```

This issue is just being opened for discussion and is a follow-up from facebook/react/issues/11094 and reactjs/reactjs.org/issues/10