Thanks @jomo for this contribution:
- Dashed language codes are accepted, e.g. `["en-US", "fr"]` will use `en`
- It also falls back to using the UI language if no usable `Accept-Language` is found
- Requests are limited to `http`/`https`
- Proper URL handling
- Extension triggers if 2nd or 3rd domain label is `google` or `youtube` (e.g. `
google.com`, `
google.co.uk`). Other Google domains exist, including `*.google` and `*.goog`, but AFAIK `hl` is not used on
- `hl` parameter insertion now works reliably (e.g.
https://groups.google.com/forum/#!overview)
