#570 - Fix server details styling

To fix #570:

1. Added css/*.css into the assets precompile path, so that CSS files like
   css/admin-tab.scss are precompiled and put into public/assets/css by
   Rails. This can then be accessed using the RailsAssetsService.

2. Made RailsAssetsService available to the VM (by putting it into its
   context). This makes each CSS or any asset file easily reference-able
   from VM pages.

3. The #if() line was in the wrong place. It was inside the
   Rails 2 block (else part of #if()). It needed to be moved
   outside.