Sport & layout fixes

- [new] `article__sub-head` is called `page-sub-header` because we use it elsewhere than articles
- [new] `page-head` is called `page-header` to match the naming convention of the designer's font scale
- [fixed] Sport pages (teams, leagues) don't look broken on tablet / desktop
- [fixed] Sections and most read pages don't look broken on tablet / desktop
- [fixed] Spacing tweaks
- [fixed] We show the standfirst in sport trails (so that the image does not stand alone on the left)
- [other] refactored and cleaned up a lot of sport-specific styling

Sorry for the quite substantial PR, as those fixes came along one after another without any clear list of things to fix.

Note that almost nothing has changed on mobile aside from a couple of spacing tweaks.

![ ](http://3.bp.blogspot.com/-V9sgZIy-FPk/Ulrw3tIVvLI/AAAAAAAAAFI/LI-RvBcozQs/s320/circle_in_circle3.gif)