Add sass and stylus preemptively for #40 and #50.

admin/generate-dev-bundle.sh

@@ -133,6 +133,8 @@ npm install gzippo@0.1.4
 npm install optimist@0.3.1
 npm install coffee-script@1.3.1
 npm install less@1.3.0
+npm install sass@0.5.0
+npm install stylus@0.25.0
 npm install mime@1.2.5
 npm install semver@1.0.13
 npm install handlebars@1.0.5beta