Hotfix: speed improvements in Rules and Online Game Menu Screen

We found out that we had a bug which is only visible when there are a ton of Online games going on at once. The framerate in the online game menu screen was like 1 fps even on a good computer. We've fixed the underlying issue & it's back at 60 fps.

The Rules screen had a similar issue... some of our 2D objects were measuring and re-positioning themselves every frame. We're caching that stuff now.

Still have more work to do on various 2D performance stuff here and there, but this was urgent so we got it out today.