[SVGMobile12] STZLC3-9 listening to document events

We did not find a way to specify a listener on an event which is received by
the document and not by an element of the scene. Such events would only be
accessible through the creation of a listener by scripting.

If this analysis is right, please specify a way to declare a listener
element observing the document.
Thanks
Nicolas Pierre, Julien Tranchant, Erwann Gouesbet and Jean-Claude Dufourd