Input extender: Listening to "animationstep" event

(bug 48677)
Requires change Ie6717ccece619b7cb8a096f016a690cda3b9ed80 in the Wikibase extension.

Change-Id: I90c806aa730949bfce1d5b21f1b3c0429ba962ff
Merge "Input extender: Listening to "animationstep" event"