Bug 1070001: Re-org Stylus - demo studio

Moved the demo studio CSS into the redesign folder.
Broke CSS into smaller files using the existing comments as a guide. Some of these are components, the way I want to organize files in the future, but some of them are not. Weird mish-mash, sorry.
Merge pull request #2842 from stephaniehobson/BUG-1070001-reorg-stylus-demos

Bug 1070001: Re-org Stylus - demo studio