Exposed baseHref to catandtag.tpl

This allows some google crawl errors to be fixed by supplying a full path to resources.
Changed relative links to full paths.

This fix uses the FAQ variable `baseHref` resolve some Google crawl errors.
Changed social networking links to nofollow.

It seems the `.pdf` documents for the FAQ are given precedence over the actual web page.
This uses `nofollow` to solve the problem by preventing page rank from flowing to the social network & `.pdf` buttons.
Added C++ and Plain brushes to syntax highlighter.
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.
Fixed RSS/Atom feed compatibility, closes #886
Improved category selection usability
Fixed sent mail to category owner, closes #891
Updated release date
Prepare release
Added missing shebang
2.8.12 -> 2.8.13
Updated Chinese (Traditional) translation
Added backported support for SQLite3
Added check to not delete the main instance
Fixed check on DB type
Fixed possible bypas of captcha by using old codes
Removed Flash based players and support
CS fixes
Fixed CSRF validation