A small patch fixing a a few bugs, missing elements.

This patch will fix a few small problems I've encountered.

- Some resources with relative links are seen as broken links due to the `<base>` tag.
- The PDF file for articles are occasionally given search precedence over the actual FAQ page, `nofollow` fixes this.
- Glossary items are injected into `<pre>` (`<code>`) tags, which results in unrendered HTML.
   It seems the injection into `h2`, `table`, and `a` seems to have been fixed.
- Added `C++` and `Plain` modes to syntax highlighter.

See the commits for more details of each change.