title: image_tag in mailer not using asset_host
body: <p>image_tag isn't using the asset_host I've set. Any ideas why? The only thing I can think of is it having to do with it being a Mailer.</p>
  
  <p><strong>config/environment/development.rb</strong></p>
  
  <pre><code>config.action_controller.asset_host = "http://localhost:3000"
  </code></pre>
  
  <p><strong>myMailer.rb</strong></p>
  
  <pre><code>&lt;%= image_tag "logo.png", :style=&gt;"margin-left:10px; padding-bottom:15px;" %&gt;
  </code></pre>
  
  <p><strong>rendered as:</strong></p>
  
  <pre><code>&lt;img alt="Logo" src="/images/logo.png?1303090162" style="margin-left:10px; padding-bottom:15px;" /&gt;
  </code></pre>
  
  <p><strong>In console:</strong></p>
  
  <pre><code>&gt; MyApp::Application.config.action_controller
  #&lt;OrderedHash {… :asset_host=&gt;"http://localhost:3000", …}&gt;
  </code></pre>
  
  <p>I need the image_tag to create a full path url because it will be showing up in an email.</p>