This reverts commit ead27b22.

This reverts commit 51db272a.

This bumps PHP version requirements to `7.1.*`.

It's prettier, and it does the job of indicating where the focus is.
We need a secondary color, to complement the blue, though.

Note that we found a "bug" in browsers, using keyboard navigation.
First, focus the language selector.
When tabbing to the next anchor, the focus is lost and the next anchor
disappears, so the element focus goes into the void and the loop resets.

Really not sure about how to solve this.

This is a simple fix, but it does the job.

We'll use zepto instead w<hen we'll need the js goodies.

It should now work on browsers with javascript disabled.
We're using a nifty checkbox hack.