Support inline compilation errors

[bvaughn]

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:

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