Fix <link/> tag for RSS feeds (#149)

layouts/_default/baseof.html

@@ -62,10 +62,9 @@
     <link rel="icon" type="image/png" href="{{ .Site.Params.favicon_32 | default "/images/favicon-32x32.png" | absURL }}" sizes="32x32">
     <link rel="icon" type="image/png" href="{{ .Site.Params.favicon_16 | default "/images/favicon-16x16.png" | absURL }}" sizes="16x16">
 
-    {{ if .RSSLink }}
-      <link href="{{ .RSSLink }}" rel="alternate" type="application/rss+xml" title="{{ .Site.Title }}" />
-      <link href="{{ .RSSLink }}" rel="feed" type="application/rss+xml" title="{{ .Site.Title }}" />
-    {{ end }}
+    {{ range .AlternativeOutputFormats -}}
+      {{ printf `<link rel="%s" type="%s" href="%s" title="%s" />` .Rel .MediaType.Type .Permalink $.Site.Title | safeHTML }}
+    {{ end -}}
 
     {{ .Hugo.Generator }}
   </head>