Update trunk/Identity/Models/Themes/Default/ directory structure:
    
        - Move Promo/Stationery/Media directory structure inside
          Distro/$RELEASE/Media directory structure. This way, we start to
          consider installation media part of CentOS Distribution
          organization. We did this to reuse the release schema of Distro
          directory structure.  So, specific design models could be
          provided to each major release of CentOS Distribution
          individually.
    
          At this moment, I think it is convenient to have all CentOS
          Distribution release-specific components inside the same
          directory structure. This way we can produce them based on the
          same release schema and provide uniformity.