moves index.html over to DRY content block
moves detail.html over to DRY content block
moves archives.html over to DRY content block
moves 403.html over to DRY content block; fixes page title for consistency
moves 404.html over to DRY content block; fixes page title for consistency
moves 500.html over to DRY content block; fixes page title for consistency
moves about.html over to flatpagecontent block