Add tests for blocking audio scheduling

Pretty much makes sense, some wierdness but nothing major.

It seems like negative volumes (only accepted by multichannel sceAudioOutput*) mean "don't change."  I didn't play around with the differently-scaled volumes for the new APIs.  Also, the new APIs seem to be the same since you can use `sceAudioOutput2Reserve()` with `sceAudioSRCChRelease()` and it's fine with that.

It also seems like we don't block at all correctly, and append to the queue when we ought to block.  I'm not sure, but it seems like the PSP doesn't actually append...

Already changed the audio thing but haven't done the blocking yet.  But, I think these tests are generally good anyway.

-[Unknown]