A component displaying its content as formatted text, respecting newlines and (optionally) parsing links

# Usage

Use this component whenever you have to show a piece of text possibly containing newlines or links, and you want to display them nicely. You can choose to format links or newlines or both independently.

The FormattedText content is typically user input: for instance, in a comments thread UI, you may want to allow the users to have minimal formatting abilities.

<img width="334" alt="screen shot 2018-03-16 at 10 57 39" src="https://user-images.githubusercontent.com/2643520/37514701-f1231aba-2908-11e8-9fd4-14f1cf130638.png">

Another possible use case is: in extremely simple layouts, e.g. a Tooltip content, you may sometimes want to display clickable links or respect newlines. The `Tooltip` component uses `FormattedText` automatically to format its content.

<img width="347" alt="screen shot 2018-03-16 at 11 27 52" src="https://user-images.githubusercontent.com/2643520/37516299-efd72dcc-290d-11e8-90cf-700db4c9f0bc.png">
