ALLOW_UNSAFE / disable Sanitizer

[adlergfx]

As developer i like to embed my own iframes and i like to style them a lot. Therefor i need the possibility to include any html/js.
Similar to ALLOWED_IFRAME_HOSTS which is in code visible but not obviously documented i would suggest to allow a define('ALLOW_UNSAFE', true) in config which simply adds in Document.class.php / sanitizeHtml:

 public function sanitizeHtml($string) {
        if (defined("ALLOW_UNSAFE") && ALLOW_UNSAFE) return $string
       ...

Sanitize is very important and should be active for regular users. For Developers it might be a great benefit to override it without modifying the code.