Now that we're sending the joint rotations for the whole skeleton and don't send the palm positions explicitly (in the AvatarData update packet) the palms of non-MyAvatar instances are never "active" (we used to use the existence of the palm-position data in that packet to mark them as active).  Hence all of the "palm-specific" code here (as opposed to the Hand-specific code) won't work.  That's OK though, because it was just the "playSlaps" stuff which is to be pulled out anyway -- we'll reimplement it via JS eventually when we can handle collision events in JS.