Improve display of news tags

Improve display of news tags

* Add a fa icon for tags to the buttons that are clicked for news tags,
  to make it more clear what they are.
* Show a badge with the tag on each item when browsing the list.
* Change the buttons to be badges when viewing an individual item, and
  move them to the top of the page instead of the bottom for consistency
  with the listing.

In passing, add some spacing between the header and the text when
viewing a news item, because it looks a lot better.