Stylus

Changes the CSS to use the Stylus preprocessor.  In addition, integrates the gulp.js build system.  Furthermore, uses gulp.js to deploy on gh-pages.

To collaborators: use `run.sh` to run the development http server while watching with gulp.js to automatically rebuild changed files.  This replaces the previous `node web.js` command.

This is a major change, integrating the gulp.js build system, therefore should bump the repo to version 0.3.0.  It will pave the way for js minification/concatenation, as well as cache busting, etc.