4 - `graceful-fs` added as an `optionalDependencies`. Thanks [ryanzim]!
9 - `filter` option to pre-filter and not walk directories.
13 - added support for custom `fs` implementation. Useful for https://github.com/tschaub/mock-fs
17 - bugfix: if `readdir` error, got hung up. See: https://github.com/jprichardson/node-klaw/issues/1
21 - assert that param `dir` is a `string`
25 - bug fix, options not being passed
29 - added `queueMethod` and `pathSorter` to `options` to affect searching strategy.
33 - removed unused `filter` param
34 - bugfix: always set `streamOptions` to `objectMode`
35 - simplified, converted from push mode (streams 1) to proper pull mode (streams 3)
42 [ryanzim]: https://github.com/ryanzim