Merge remote-tracking branch 'upstream/master' into upstream

* upstream/master:
  facebook sharing image meta tag added related mmistakes#149 issue
  Show related posts only when there are 1 or more

_includes/_open-graph.html

@@ -16,4 +16,9 @@
 <meta property="og:title" content="{% if page.title %}{{ page.title }}{% else %}{{ site.title }}{% endif %}">
 {% if page.excerpt %}<meta property="og:description" content="{{ page.excerpt | strip_html }}">{% endif %}
 <meta property="og:url" content="{{ page.url | replace:'index.html','' | prepend: site.url }}">
-<meta property="og:site_name" content="{{ site.title }}">
+<meta property="og:site_name" content="{{ site.title }}">
+{% if page.image.feature %}
+<meta property="og:image" content="{{ site.url }}/images/{{ page.image.feature }}">
+{% else %}
+<meta property="og:image" content="{% if page.image.thumb %}{{ site.url }}/images/{{ page.image.thumb }}{% else %}{{ site.url }}/images/default-thumb.png{% endif %}">
+{% endif %}

_layouts/post.html

@@ -55,6 +55,7 @@ <h1><a href="{{ site.url }}{{ page.url }}" rel="bookmark" title="{{ page.title }
 </div><!-- /#main -->
 
 <div class="footer-wrap">
+  {% if site.related_posts.size > 0 %}
   <div class="related-articles">
   <h4>You might also enjoy <small class="pull-right">(<a href="{{ site.url }}/posts/">View all posts</a>)</small></h4>
     <ul>
@@ -64,6 +65,7 @@ <h4>You might also enjoy <small class="pull-right">(<a href="{{ site.url }}/post
     </ul>
     <hr />
   </div><!-- /.related-articles -->
+  {% endif %}
   <footer>
     {% include _footer.html %}
   </footer>