Update templates

The following updates are made:
- index.html now lists the site description along with X articles
- _list_item.html universalizes code for iterating over the articles
- _site_social.html is merged into base.html
- _google_search.html is added for custom search support
- _gosquared.html, _google_analytics.html have minor formatting changes
- archives.html displays a one page list of all articles
- period_archives.html is removed as it is not planned for implementation atm
- tags.html general clean up and tweaks
- base.html now has
  - full rss/atom feed support
  - disqus comment count support on links (not used yet)
  - blog links in aside
  - search in aside

templates/_google_analytics.html

@@ -1,5 +1,5 @@
-<!-- Google Analytics -->
-<script type="text/javascript">
+  <!-- Google Analytics -->
+  <script type="text/javascript">
     (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
       (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
     m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
@@ -7,6 +7,4 @@
 
     ga('create', '{{ GOOGLE_ANALYTICS[0] }}', '{{ GOOGLE_ANALYTICS[1] }}');
     ga('send', 'pageview');
-
-</script>
-
+  </script>