JS Media Queries, responsive Kwicks

- You can now basically do media queries via JS - see the bottom of
layout.scss
- Kwicks is now responsive from a JS perspective; it turns off whenever
the window is "small" or "extra-small" (whether via resize or it was
just loaded that way). Everything works as expected in medium and large.
There's a lot of CSS still to be written for the small and extra small
varieties.