Additions to Octopress atom.xml to allow for RSS mapping to external URLs.

atom.xml

  {% for post in site.posts limit: 20 %}
  <entry>
    {% if post.external-url %}
	<title type="html"><![CDATA[{{ post.title | cdata_escape }}]]></title><!-- add in a glyph or [link-post] here so people know where they're ending up -->
	<link href="{{ post.external-url }}"/>
	{% else %}
	<title type="html"><![CDATA[{{ post.title | cdata_escape }}]]></title>
	<link href="{{ site.url }}{{ post.url }}"/>
	{% endif%}
    <updated>{{ post.date | date_to_xmlschema }}</updated>
    <id>{{ site.url }}{{ post.id }}</id>
    {% if post.external-url %}
    <content type="html"><![CDATA[{{ post.content | expand_urls: site.url | cdata_escape }}<a rel="full-article" href="{{ site.url }}{{ post.url }}">Permalink</a>]]></content><!-- add in a glyph or some way to denote that the permalink goes back to your site -->
	{% else %}
    <content type="html"><![CDATA[{{ post.content | expand_urls: site.url | cdata_escape }}]]></content>
	{% endif%}
  </entry>
  {% endfor %}