Last explicit cast seen.

[jjceresa]

Explicit casts to avoid narrowing conversion warnings.

[derselbst]

I dont like it. It makes this macro magic even more complicated. But I'll take it and will probably take care of that in #197, by using unions and the same function signature for every rvoice_event_handler function. That will hopefully allow us to get rid of this huge switch case and call the functions directly.