Highlight stickied comments; don't dim downvoted stickies.

The highlight color uses the same color as the subnav bar background
color. Make it a tad brighter so it's more visible.

app/assets/stylesheets/specific/comments.css.scss

@@ -15,6 +15,11 @@ div.comments-for-post {
     article.comment {
       margin-bottom: 2em;
       word-wrap: break-word;
+      padding: 5px;
+
+      &[data-is-sticky="true"] {
+        background: $menu_color;
+      }
 
       div.author {
         width: 12em;
@@ -40,7 +45,7 @@ div.comments-for-post {
       }
     }
 
-    article.comment.below-threshold {
+    article.comment.below-threshold:not([data-is-sticky="true"]) {
       opacity: 0.3;
     }