Background Engine API

This was a big one. After wrestling last night and this morning with a weird memory leak that only showed itself during debugging (not during normal play), and then vanished later, and a lot of refactoring to pull all the controls into a single, elegant obj_background_manager, it’s stable, playable, and apparently bug free…?

I still have plenty of big background features I’d like to implement from yesterday’s list, and then:

  • Go through the waves and add features that make sense: currently, I only set the features in the first wave, and they’re boring by the end.

Good fun, though. Version bumped, pushed, and sent out for playtesting and kudos.