Add support for the Open Arena missionpack

#1

I know this missionpack is a bit prototypical (for my taste at least), but is it possible to give Spearmint support for it? Should be named something like “oamissionpack” or “oamp” or something like that. I would like to see support for it in the forseeable future, @zturtleman.

#2
#3

Thanks @zturtleman! So it’s set up as missionpackoa then…

#4

It seemed like missionpackoa fit with the baseoa naming.

#5

That makes sense (the naming scheme at least)…