Pages addon

Event needed for Page addon
This entire block needs to define the variable types and have better variable descriptions.
```php
* @var string content               Page content
* @var string route                 Page route
* @var string uid                   Page content bbcode uid
* @var string bitfield              Page content bbcode bitfield
* @var int    options               Page content bbcode options
* @var bool   content_html_enabled  Is HTML allowed in page content
```