title: Use assetic output in config.yml
body: <p>I'm using assetic in a Symfony 2.4 project to generate and compress my CSS.
  I'm also using some bundles that need a CSS in their configuration, like <em>content_css</em> parameter of <a href="https://github.com/stfalcon/TinymceBundle" rel="nofollow">stfalcon tinymce</a> bundle. For those who don't know it, this bundle package the use of <em>tinymce</em> to provide rich text editor. <a href="https://github.com/stfalcon/TinymceBundle#custom-css" rel="nofollow"><em>content_css</em></a> configuration item allow to set the CSS that will be used to display the text in the rich editor.</p>
  
  <p>My problem is that I don't know the name of the css because it's generated by assetic, and so cannot provide the correct <em>content_css</em> in <em>config.yml</em>. How can one handle this kind of situation? Is there a better way than getting a static css only for this bundle, with all the mess of keeping it current?</p>