Threading conundrum about arrp

[Devan-Kerman]

using the same executor service won't work in the event a mod decides to wait on an async task for whatever reason. I should have used a lock, and for some reason didn't. I think rrp is in need a big upgrade though, since modders can't choose the priority of the resource pack, along with the inefficiencies of using String#format for templating, and then creating a byte array from that

[Devan-Kerman]

I've rewritten the whole thing from scratch, will commit soon:tm: once wiki is done, I think the threading is much better this time

[Devan-Kerman]

Well there you go, all done I think