title: What exactly "config.assets.debug" setting does?
body: <p>I have started development of simple rails application. After several hours work I have notices that somehow the deleted css is still applied to the web pages. </p>
  
  <p>In order to fix the issue I executed the following actions several times:</p>
  
  <ol>
  <li>stop/start server</li>
  <li>use rails server</li>
  <li>use torquebox server</li>
  <li>delete browser cache</li>
  </ol>
  
  <p>but nothing changes. It was very strange - the new css definitions were applied, but those that I have deleted were still there. So, I gave up and decided to create new project.</p>
  
  <p>I have setup the new project (its scaffold is the same as the first one) and when I open one of the views, the styles from the old project were applied too. I have decided to look again into <a href="http://guides.rubyonrails.org/asset_pipeline.html" rel="noreferrer">http://guides.rubyonrails.org/asset_pipeline.html</a> and find out that setting </p>
  
  <pre><code>#Expands the lines which load the assets
  config.assets.debug = false
  </code></pre>
  
  <p>solves the issue. But what is this option doing exactly? Why the old projects css were applied when this was true?</p>