Clean all the things

This release is mainly just tidying up things based on linting and opinions. So I have removed silly things such as that almost blank .jshintrc file which stopped your own ~/.jshintrc working when you were editing any EventEmitter code.

@desandro also submitted a pull request about a bug he found when nesting listeners. I have since improved the tests hugely but still can't reproduce the issue he found. I have merged in that change anyway because it should make the code more robust.

So, no new features, just hardening and cleaning. Enjoy!