Previously, a legacy client wouldn't get a VoIP packet, but if they did,
they'd panic and disconnect. Now they ignore them and continue on. This also
gives us the framework to add other features legacy clients can ignore.
Oh, this also has the benefit of allowing us to store incoming VoIP for
playback in recorded demos. They'll play the chatter on VoIP clients, and
be ignored on legacy ones. Huge win.