Security rules, sample app and extensibility

The setText() method of HTML objects now only accepts <br>, <wbr> and
<a> tags.
The sample apps is now the source code of the LEOPS webpage.
HTML class no longer refer to itself with $this-> but with
$this->getRootElement()->. This allow classes that extends HTML to set
another element as the root (for instance in the Nav component it is the
<ul> or the <span>depending of the type of the nav).