Issue: Recursive Templates

Since we are adding MediaWiki import support in this next build, we have to add support for template recursion which MediaWiki natively supports.

Instead of simply pasting the text, we have to nest a $this->parse() call, so that additional templates can be found. Instead of limiting the recursion count as in earlier VaultWiki builds, we need to implement the MediaWiki method of disallowing the same template to be parsed in a later recursion.