* Add a `coffeelint` check.
* Do not load `execjs` unless JavaScript checks are enabled
* Load checks with [pluginator](https://github.com/rvm/pluginator)
* Allow configuration of warnings (log to `stderr`, but do not abort the commit) in `git config pre-commit.warnings`
* Use the Apache 2.0 liscense
* The `nb_space` check reads files in utf-8