Update N64 Core

Edit: Briefly updated to reflect changes since the initial issue was opened.

Originally, I posted this as an issue regarding a much-needed update to the Mupen64Plus core in Bizhawk. Here's the original issue: The Mupen64Plus core has undergone a lot of changes and has seen a lot of improvements since it's original implementation, and it would be nice to see these improvements make their way in to Bizhawk.

Unfortunately, at the current point, the Bizhawk implementation of GLideN64 (when compared to the same version of the plugin that was implemented) is inferior. There are numerous problems which simply are non-existant when the same version is used with Mupen64Plus Project 64. Mupen64Plus also receives updates alongside GLideN64 to allow more titles to run and fix problems of the two in tandem.

There are also other bugs that can be squashed with newer plugins to accompany this change, such as #711, which is no longer an issue with the latest "Project 64 sound plugin", Azimer's audio plugin also apparently received an update to work with Mupen64Plus, which might a better option.

Also, some personal notes: I know the original implementation was a lot of work and there would be lot of things to consider, but I thought now would be a good time to bring it up and having an issue open would be a the best way to do so.

[vadosnaprimer]

Actually right now isn't exactly the good time for that, because micro500 is so busy, and we're moving to x64, which will cause a bunch of bug reports until it's done perfectly. Maybe later someone will be able to try blah blah, but I wouldn't expect that soon. Updating GlideN appeared to be easy it seems, it just took updating the submodule. The core has been heavily modified by both parties, so it can't be reliably easy.

That's alright, I knew of how busy micro500 was when I posted it so I fully expected a long wait. It's only an enhancement (the existing core is perfectly functional), so that's not really a problem for me at least, and the move to x64 is what prompted me to post this.

Just on the off-chance there were some really large issues resulting in a rewrite of the core (unlikely), it would suck if large amounts of effort were put into redoing the old one when a new version exists. I honestly didn't expect GLideN64 to be updated so easily, so I'm still excited to see what improvements it's brought with it.

[vadosnaprimer]

Developer build now links to the waterbox2 branch, so you can test it right away,.