Added fix for abbr tags in code.
Added fix for abbr tags in code.

The PHpMyFAQ system currently adds glossary entries into `<code>` tags.
As they are embedded within `<pre>` tags, the `<abbr>` tags are not rendered as html,
but as plain text inside other code.
thorsten/phpMyFAQ,thorsten/phpMyFAQ,thorsten/phpMyFAQ,thorsten/phpMyFAQ