Adds Antialiasing support to Glide64mk2 with adjustable settings in the cfg file.

Sorry it took so long. Someone requested this in the message pool and I figured I'd give it a whirl. I've never used git for anything but obtaining source before now.

Anyway, the end result is an extra setting under the Glide64mk2 section called wrpAntialiasing. Put in a power of two for the sample count and it should apply it to the window when launched.