ce0d3112e4
Remane sound_scene_handle to playback handle. sound_scene_handle was a part of scene so we could see code like scene- often in the same function. If I understand things correctly, in audaspace lingo, the playback_handle corresponds to a Reader while the scene_sound corresponds to a Factory. More cleanups will be done here later, but changing this now because my brain hurts trying to remember which is which...