Merge branch 'master' of github.com:dementrock/mitx into brittany

lms/templates/discussion/_trending_tags.html

+Trending tags:
+
+<div class="trending-tags">
+  % for tag in ['artificial-intelligence', 'java-sucks', '2012']:
+    <div class="trending-tag">
+      <a class="trending-tag-link" href="javascript:void(0)">${tag}</a>
+      &times;
+      <span class="trending-tag-count">100</span>
+    </div>
+  % endfor
+</div>