Provides a toolbar icon. Clicking it produces a drop-down menu, containing 5 items. Each of these enables displaying one of the item classes which the tool blocks. Changes affect only the current web page: if you click through to another page, they reset to blocking all classes.
Deficiencies:
* There is no way to re-hide something for the current video (eg video suggestions) after enabling it.
* The menu is bulky. It could be made less verbose. Eg: "show in-video video suggestions" -> "in-video suggestions".
