Use pure CSS only (for compatibility with our OBS packages)

 * In a regular setup, everything will work as expected using the asset pipeline
 * For our packages, everything will work just copying application.css into
   [obs]/public/stylesheets/obs_factory
 * The only drawback is that we will not have digest for application.css, but I
   guess we can live with it.
Merge pull request #8 from ancorgs/pure_css

Use pure CSS only (for compatibility with our OBS packages)