Remove default `figure` margin

Normalize.css 3.0.0 restored the default `figure` margins, so we remove
them for the web app context.
Add base theme variables

Provide the ability to easily configure base typography and color theme
for `html` and `a`.
Depend on Normalize.css 3.0.x
Better fallbacks when variable values are missing
Minor addition to rendering test file
Process CSS before builds; drop CSSLint

* Use 'component-builder-suit' to process the CSS for tests and
  generating app builds.

* Stop using CSSLint. It complains about the custom properties syntax
  and isn't providing enough value for this approach.
Add standalone build command
Automatically rewritten for npm.