Dev Update: More mod support and big under-the-hood physics refactoring

Hey guys, not a big deal with this dev snapshot but I made some medium-sized under-the-hood changes to the engine to help simplify NPC stuff. It involved a lot of changes to physics management and might break stuff (I think ship crashing is broken) :P

Also improved mod support even more. Now music and shaders should actually be supported.

Figured I’d update the dev build so modders could take a look. And if you notice new crashes or physics-related problems, let me know!

PS: I also took the green/red LOS lines out.