title: Add folder to asset pipeline path?
body: <p>We have a rails app that I recently updated from Rails 3.0 to Rails 3.2. This app services multiple clients. To customize it for each client, we have the directory <code>app/themes</code>. In there are submodules. Each submodule contains things like <code>locales/en.yml</code>, <code>views/layouts</code>, <code>views/controller_name</code>, etc. We use the <code>prepend_view_path</code> to add the theme views, and the <code>I18n.load_path</code> to add in the locales. We're looking at using the asset pipeline so we can keep all the mix of client material out of the public directory, and keep it contained in each theme. </p>
  
  <p>Is there a way i can dynamically tell rails to load which theme/theme-name/assets folder i want? We use settings logic to set which theme is active. So if i have the theme set to "google", the <code>ApplicationController</code> then loads files from the path:</p>
  
  <pre><code>app/themes/google/locales/*.yml
  app/themes/google/views
  </code></pre>
  
  <p>What I'd like to be able to do is have the manifest file,</p>
  
  <pre><code>app/themes/google/assets/stylesheets/application.css
  </code></pre>
  
  <p>easily accessible to the layout, much like you would in an <code>app/views/layouts</code> file: </p>
  
  <pre><code>= stylesheet_link_tag "application"
  </code></pre>
  
  <p>Is there a way i can do this? or do we need to manually move the assets into the actual assets directory?</p>