Also, add a missing license header in build/workbox.js.

* Update copyright range to include 2018

* Extend copyright date range on new files from 2017 to include 2018

Also, refactor ESLint and stylelint config files; now everything will work from our root dir.

Also, include it in the `css` npm script since it's instant.

* "autocomplete" attribute errors
* "legend" is not allowed as child of "div"

* rename build/htmllint.js to build/vnu-jar.js
* remove the unused `bash` script
* split the `docs-lint` scripts
* fix watch-js script to run only the parent `js-compile` script

The option is set to `always-single-line` in stylelint-config-standard which we extend.

This saves a few bytes from the unminified dist files.

We actually want to generate a sourcemap for docs.min.css.