Merge pull request #1286 from SamWhited/master

Use protocol relative URL's for Twitter

.themes/classic/source/_includes/post/sharing.html

@@ -1,6 +1,6 @@
 <div class="sharing">
   {% if site.twitter_tweet_button %}
-  <a href="http://twitter.com/share" class="twitter-share-button" data-url="{{ site.url }}{{ page.url }}" data-via="{{ site.twitter_user }}" data-counturl="{{ site.url }}{{ page.url }}" >Tweet</a>
+  <a href="//twitter.com/share" class="twitter-share-button" data-url="{{ site.url }}{{ page.url }}" data-via="{{ site.twitter_user }}" data-counturl="{{ site.url }}{{ page.url }}" >Tweet</a>
   {% endif %}
   {% if site.google_plus_one %}
   <div class="g-plusone" data-size="{{ site.google_plus_one_size }}"></div>

.themes/classic/source/_includes/twitter_sharing.html

@@ -4,7 +4,7 @@
       var twitterWidgets = document.createElement('script');
       twitterWidgets.type = 'text/javascript';
       twitterWidgets.async = true;
-      twitterWidgets.src = 'http://platform.twitter.com/widgets.js';
+      twitterWidgets.src = '//platform.twitter.com/widgets.js';
       document.getElementsByTagName('head')[0].appendChild(twitterWidgets);
     })();
   </script>