Adding Initial Redesign Structure

This adds the initial stylus files and stub HTML pages built out.  A few notes:

1.  Stubs can be found at these endpoints:

/en-US/redesign/stub/article
/en-US/redesign/stub/zone
/en-US/redesign/stub/search_results

2.  "redesign" waffle flag is there (used in templates/base.html) to use that template instead.

This is a progress PR so people can see how things look at the moment.  The "mobile" and "mobile-wide" media queries look crappy, but desktop and "tablet" look fine.  Mobile will be an ongoing specificity update.