Always forward all events in the default handler. Previously it used to not
forward caps events by default. It makes more sense to forward the caps events,
if the element is interested in the caps, it will implement an event handler to
retrieve the caps and then it can decide to forward or not. If the element has
no event handler, it probably just doesn't care about caps and it probably is
also not going to modify the data in a way that needs a caps change.