Bring back "media-only" button. Still non-functional.
This does it, except the box is unchecked...
 I am not sure how it would work for a page (that automatically does a search) to have a box checked by default. Maybe we should reverse the sense of the box? Also: does "Media" = video+audio?
Merge pull request #970 from afred/media-only-938

Media only 938