Neo Geo implementation complete (transcode bugs aside)!!!

Sprite optimisation is - to the best of my knowledge - complete!

I had some time tonight to look at 2x2 tile sprite flipping, noticed that in my previous "shortcut" attempt I had made an error, fixed it... and it worked! I also verified that 1x2 sprites are never Y-flipped, so I don't need to handle this case (a similar strategy would have worked anyway).

Without going into detail, multi-level 'switch' statements have been avoided, as have look-up tables, with some convenient bit-wise operations. Quite neat in fact (and probably how the arcade hardware actually works). And the logic can likely be used in the Amiga implementation as well!

The Solvalou explosion is finally correct!

So this means that (sound aside) the Neo Geo implementation is now complete!

I will give it a final run, with a very close look at video quality, on the AES when I next get a chance.

Next task is a full audit of the RE & transcode - Z80 vs 68K - and fix the remaining few gameplay bugs in the process. This might take me a few weeks. Then I can finally dive into the Amiga implementation and try to learn a thing or two while I give jotd a hand to finish it off, before we work on the sound together.