HTML5 export

[konsumer]

It'd be cool to somehow export to HTML5, or at very least fallback to ogg files with same name. Looks like someone ported libopenmpt to webasm here, but I'm not sure how godot export works with javascript libs.

[konsumer]

I tested the web demo just by dragging files onto the drop-image, and it worked great with mods, but didn't handle spc or nsf files. this may just be a problem with the demo, but it might need something else.