It is not relevant for the connection stage so it should not have
been a constructor argument to begin with. Ship with a warning for
a release before we remove it.
* First attempt to make the fullscreen button work inside an iframe.
* Cleaner distinction between document element and document.
* Scoping corrections. Auto-detect correct iframe.
* Added comments to the relevant sections.
* IE issue fixed.
* Same source issue solved. fullscreenToggle now checks if it is permitted to inspect other iframes.
