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.