Assets restructure

assets are now restructured to be neat. the reason for doing it is to be consistent with rails asset pipeline.

please refer to _/app/assets/javascripts/application.js.coffee_ and _/app/assets/stylesheets/application.css.scss_ for how the files are now loaded.

* to add additional custom javascript quickly, add it to _scripts.js_
* to add additional custom styling quickly, add it to _styles.css_

for local development, assets are compiled on the fly. i think, heroku will compile assets automatically upon deploy.