title: Glyphicons not properly precompiling in Production Rails
body: <p>With Rails 4 I have run into an issue where glyphicons from Bootstrap are not being properly precompiled.  The below is generated:</p>
  
  <pre><code>started GET "/assets/glyphicons-halflings-white-ed38e147e3f6e976c0a7ad59e4d628f3.png" for          127.0.0.1 at 2014-01-13 18:41:25 -0500
  Started GET "/assets/glyphicons-halflings-white-ed38e147e3f6e976c0a7ad59e4d628f3.png" for 127.0.0.1 at 2014-01-13 18:41:25 -0500
  Processing by ApplicationController#routing_error as PNG
  Processing by ApplicationController#routing_error as PNG
    Parameters: {"path"=&gt;"assets/glyphicons-halflings-white-ed38e147e3f6e976c0a7ad59e4d628f3"}
    Parameters: {"path"=&gt;"assets/glyphicons-halflings-white-ed38e147e3f6e976c0a7ad59e4d628f3"}
    Rendered public/404.html (0.3ms)
    Rendered public/404.html (0.3ms)
  Completed 404 Not Found in 17ms (Views: 3.4ms | ActiveRecord: 8.0ms)
  Completed 404 Not Found in 17ms (Views: 3.4ms | ActiveRecord: 8.0ms)
  </code></pre>
  
  <p>It works fine in development.  And if I set <code>config.assets.compile = true</code> in production.rb it seems to work fine - but I understand that to be very bad based on this SO question:
  <a href="https://stackoverflow.com/questions/18608731/files-produced-by-assetprecompile-dont-match-urls-generated-by-stylesheet-link/18608732#18608732">files produced by asset:precompile don&#39;t match urls generated by stylesheet_link_tag (missing digest) in minimal rails 4 site</a></p>
  
  <p>This was not an issue for me in Rails 3.2.</p>
  
  <p>Any help would be greatly appreciated!</p>