Rewrite grids with better support for maximum width layout

Although there is a huge problem with this: adding / removing layouts will completely break other modules because we use `min-width`/`max-width` ranges. Adding a layout will create "no layout ranges"…

To be able to change layouts safely we need a mobile-first approach that only uses a `min-width` approach.

So I'm just popping this first shot at rewriting the grid module but I'll actually rewrite a big part of it with a mobile-first approach.