FileInput should support "directory" prop

Environment

• Package version(s): not applicable
• Browser and OS versions: not applicable

Feature request

FileInput does not support mozdirectory, directory, webkitdirectory or nwdirectory.

Per https://github.com/facebook/react/issues/3468#issuecomment-328197124 React does not support this specifically but the props can be added.

This feature allows selecting a directory itself vs files inside a directory.

Examples

Instead of having to define all 4 props above, directory could be used to add all at once.