Fix the exit code.

- Make exit code respect the depcheck result.

Not declare peer dependencies.

- This is no feature in this release.
- The peer dependencies are not declared in `package.json` to avoid npm install warning and errors.
- However, the feature and usage are the same.

Support more specials!

- **Deprecate** the `dev` CLI and API option, which is causing wrong missing result when `dev=false`.
- Support [commitizen](https://www.npmjs.com/package/commitizen) configuration adaptor
- Support [gulp-load-plugins](https://www.npmjs.com/package/gulp-load-plugins) lazy loaded plugins

Support more parsers!

- Support Typescript syntax (by `typescript` as peer dependency)
- Support SASS/SCSS syntax (by `node-sass` as peer dependency)
- Support parser used in feross standard linter.
- Fix bug about calculate missing dependencies.

Make option work better.

- *Breaking change*: the parser glob matcher works on file path.
- *Breaking change*: Do not output help message on CLI exception.
- Refine the code structure.

More features, bigger scope!

- [*Feature*] Figure out the missing dependencies in `package.json`, show them in JSON view.
- [*Feature*] Figure out each dependency's usage, show them in JSON view.
- [*Feature*] Recognize tranforms used in babel-plugin-react-transform.
- [*Feature*] Detect dependencies in default mocha opts file.
- Show error call stack in JSON view.
- Fix peer dependencies from nested files not detected.
- Fix the asynchronous IO output
- Specify node engine version in `package.json`.

Fix bug to handle peer dependencies from nested file.

Enjoy special parsers

- **Breaking**: Not ignore all binary packages by default. Because the bin special parser could handle better in this case.
- **Breaking**: Deprecate node version 0.10 support.
- **Highlight**: Enable all special parsers by default.
- Detect packages used by Babel presets and plugins.
- Detect packages used by ESLint configurations.
- Detect packages used as webpack loaders.
- Recognize packages used as peer dependencies or optional dependencies by another dependency.
- Enable new ES7 syntax provided by babylon.
- Fix issue about TypeError information is lost in JSON output.

Release 0.5.9 back to depcheck.

- Integrate depcheck-es6 fork back to depcheck.
- There is no function differences between this and depcheck-es6 0.5.8.

Support ES7 syntax.

- Leverage Babel parser - babylon to parse ES7 codes.
- Design change: parser returned string array is marked as dependencies and skip detector step.
- Design change: package dependencies is passed to detector and detector only return determined package now. Ready for depcheck#99.