Exclude code elements from being hidden

Due to good ol' English ambiguity, HTML `<code>` blocks that assign themselves `class="comments"` almost always mean something entirely different from any other tag with the same class. The first commit in this pull request makes an exception for `<code>` elements (unless, I am told, one is using IE8 or lower).

The second commit in this request takes the liberty of removing a superfluous `.Comments` selector midway down the document.